User Manual. NetCom PRO/WLAN. Edition: April 2012

Transcription

1 User Manual NetCom PRO/WLAN Edition: April 2012 Tel: Fax: Web: Support: service@visionsystems.de

2 The software described in this manual is furnished under a license agreement and may be used only in accordance with the terms of that agreement. Copyright Notice Copyright Vision Systems. All rights reserved. Reproduction without permission is prohibited. Trademarks VScom is a registered trademark of Vision Systems GmbH. All other trademarks and brands are property of their rightful owners. Disclaimer Vision Systems reserves the right to make changes and improvements to its product without providing notice. Vision Systems provides this document as is, without warranty of any kind, either expressed or implied, including, but not limited to, its particular purpose. Vision Systems reserves the right to make improvements and/or changes to this manual, or to the products and/or the programs described in this manual, at any time. Information provided in this manual is intended to be accurate and reliable. However, Vision Systems assumes no responsibility for its use, or for any infringements on the rights of third parties that may result from its use. This product might include unintentional technical or typographical errors. Changes are periodically made to the information herein to correct such errors, and these changes are incorporated into new editions of the publication. April 2012 NetCom PRO User Manual 2

3 Contents Contents 1 Overview 11 2 Introduction About this Manual Features Product Specifications Common characteristics Device specific Characteristics NetCom 113 PRO NetCom 411 PRO NetCom 413 PRO NetCom 811 PRO NetCom 813RM PRO (19 ) NetCom 1611RM PRO (19") NetCom 1613RM PRO (19") NetCom 123 WLAN NetCom 423 WLAN NetCom 823RM WLAN (19") Packing List Hardware Description Serial Port Configuration Signal Assignment RS 422/485 Electrical Configuration Termination Resistors BIAS Function Serial Port Simple Settings Network WLAN Configuration WLAN Antenna Ethernet Power Supply Terminal Block Power AC Power Plug Windows Virtual COM Driver Installation Procedure Start the Installation Wizard Find and Configure NetCom Devices Configure IP Parameters Configure Firewall Install Drivers Verify the Installation Update the Drivers and Tools Configuration of the Virtual COM Driver Configure the Serial Ports Performance Issues April 2012 NetCom PRO User Manual 3

4 Contents Network & Misc Properties Remote Settings Properties Installation of NetCom Servers Changing the Installation Uninstall the Drivers and Tools Configure with NetCom Manager Starting NetCom Manager NetCom Server Settings Info NetCom Server Settings Ports NetCom Server Settings Firewall NetCom Server Settings Options Manual Detection/Installation of a NetCom Firewall Traversal Configuration SOHO Firewall example SOHO Virtual Servers NetCom Detection through SOHO Firewall Serial Ports through SOHO Firewall DMZ and Virtual Servers NetCom Helper Service Configure Helper Service Detection and Priority Broadcast Search DNS based Search DNS based Firewall Configuration Changed IP Address Broadcast Domain Internal DNS Internet Polling Period Dynamic IP Address and OpenVPN Configure the Operation Modes Accessing the Configurations Web Browser Configuration Telnet Configuration Serial Configuration NetCom Configuration Options Server Configuration Server Info Server Parameter Wireless Parameter Encrypted Communication Generating strong keys Authentication Date & Time Save Serial Port Configuration Serial Settings Transfer Settings April 2012 NetCom PRO User Manual 4

5 Contents Driver Mode TCP Raw Server TCP Raw Client Null Modem Tunnel TCP Advanced Settings UDP Data Transfer IP-Modem Print Server Function PPP Network Configuration Save NetCom Tools Ping Statistics Netstat Wireless Firmware Save and Load Configuration Logging and Debug Save Reboot Save&Exit Menu Save Parameter Exit Reboot Erase Configuration of NetCom IP Modem Function Some possible Scenarios Serial Signals and Cables Operation Modes by IP Modem Hayes Commands AT command set Standard AT-Commands Extended AT-Commands Non-AT commands S-Registers for Configuration Sample Commands used by Windows Description of AT Commands AT D (dial) AT O (online / data mode) AT A (answer call) AT B (modulation) [ATB1] AT E (echo) [ATE1] AT Q (quiet) [ATQ0] AT V (verbose) [ATV1] AT H (hangup) [ATH0] AT I(n) (information) [ATI0] AT S (setup) AT L (loudness) April 2012 NetCom PRO User Manual 5

6 Contents AT M (speaker) AT N (auto baud) [ATN0] AT Z (reset) AT &F (factory settings) [AT&F0] AT &C (DCD configuration) [AT&C1] AT &S (DSR configuration) [AT&S0] AT &D (DTR configuration) [AT&D2] AT &K (handshake) [AT&K3] AT \Q [AT\Q3] AT &V (view profile) AT &W (save profile) AT &Z (save destination) Print Server Operation Printer Queue Printer Reset Init String Definition ASCII Text ASCII Control Codes Numeric Codes Modem Control Signals Timing Options Reset Example Operation in Windows Add a New Printer Create new printer port Name the new Printer Port Configure the Printer Port Install Printer Driver Modify an Existing Printer Open the properties Add the Print Server Port OpenVPN Encryption OpenVPN Installation NetCom OpenVPN Configuration OpenVPN Configuration OpenVPN Configuration File Start OpenVPN by Context-Menu Start OpenVPN by Command line Start OpenVPN as Windows Service OpenVPN without Encryption Reconfigure Virtual Serial Ports for OpenVPN PPP Network for Dial-In and -Out PPP User Accounts PPP Accounts for Dial-In PPP Accounts for Dial-Out PPP Hardware PPP Modem Commands April 2012 NetCom PRO User Manual 6

7 List of Figures PPP Null Modem Configuration PPP Networks PPP Client PPP Server TCP/IP Description Recommended Settings Static Configuration DHCP Configuration Automatic Configuration (APIPA) Other Configuration Troubleshooting Guide Glossary of Terms History 139 List of Figures 1 NetCom 113 PRO Top, Front and Rear Side NetCom 411 PRO Top and Front Side NetCom 413 PRO Top and Front Side NetCom 811 PRO NetCom 813RM PRO NetCom 1611RM PRO Front side NetCom 1611RM PRO Front side NetCom 123 WLAN Top and Front Side NetCom 423 WLAN Top and Front Side NetCom 823RM WLAN Front Side NetCom 823RM WLAN Rear Side Connector DB9 male RS 422/485 Option Jumper Master Switch Standard Configuration Power Terminal Block AC Power input Installation Wizard NetCom Driver Installation Start Driver Installation Copy Driver Files Discover and Select NetCom Devices for Installation NetCom in Manager Define NetComs IP Configuration DNS Name for NetCom Server Sending Parameters to a NetCom Virtual Com Ports installing New Hardware Wizard Install drivers for the serial ports VScom drivers in the Start Menu April 2012 NetCom PRO User Manual 7

8 List of Figures 30 NetCom in Device Manager NetCom Manager NT NetCom COM Port Serial Settings NetCom COM Port Performance Settings NetCom COM Port Network/Misc Properties NetCom COM Port Remote Settings Properties Select NetCom to install Excluded NetCom NetCom Manager Ports View Reconfigured NetCom found Replaced NetCom found Uninstall NetCom Drivers via Control Panel Uninstall NetCom Drivers in Start Menu Remove, Repair NetCom Manager NetCom Manager in Start Menu NetCom Manager Servers Panel NetCom Manager Server Settings - Info NetCom Manager Server Settings - Ports NetCom Manager Server Settings - Firewall NetCom Manager Server Settings - Options NetCom Manager Port Configuration for Driver NetCom Helper Service Enter Qualified Domain Name Configuration Menu in Web Browser Request to Reboot in Web Browser Password Request in Telnet Select Terminal Type in Telnet Main Menu of Configuration Console in Telnet Server Information Server Parameter Web Interface Server Parameter Telnet Interface Ethernet Operation by Software Wireless Parameter Wireless Encryption Modes OpenVPN Network Parameter OpenVPN Encryption grades OpenVPN Key Management in Web Browser Sample OpenVPN Key in Telnet Use new Key in Telnet Access Authentification Date & Time Retrieval Options Port Page Selection in Web Browser Port Selection in Telnet Serial Settings Operation Mode by Software Advanced Flow Control Serial Port Mode Selection Driver Mode parameters April 2012 NetCom PRO User Manual 8

9 List of Tables 79 TCP Raw Server parameters TCP Raw Client parameters Null Modem Tunnel TCP Advanced Settings UDP Data Transfer IP-Modem Print Server Configuration PPP Configuration Ping and Response in Web Browser Ping and Response in Telnet Statistics Port Selection Port Statistics Start Netstat Netstat Sample Output WLAN Scan WLAN Scan Output Firmware Upload Save and Load Configuration in Web Browser Syslog & Debuglog Parameters Menu Save modified Parameters in Telnet Menu Exit from Configuration in Telnet Exit and Reboot in Telnet Add a printer Select Printer Port Create Printer Port Name-Properties of Print Server Port Mode-Properties of Print Server Port Select Port for Printer Add Printer Port OpenVPN Installation Wizard OpenVPN Installable Components Installing TAP-Win32 Adapter OpenVPN Network Adapter OpenVPN Configuration File Context-Menu of OpenVPN OpenVPN Connection is active OpenVPN by Command line OpenVPN as Windows Service Start OpenVPN Service Service Options Startup Types Null Modem Connections List of Tables 1 Specifications, common Characteristics of NetCom 113 PRO Characteristics of NetCom 411 PRO April 2012 NetCom PRO User Manual 9

10 List of Tables 4 Characteristics of NetCom 413 PRO Characteristics of NetCom 811 PRO Characteristics of NetCom 813RM PRO Characteristics of NetCom 1611RM PRO Characteristics of NetCom 1613RM PRO Characteristics of NetCom 123 WLAN Characteristics of NetCom 423 WLAN Characteristics of NetCom 823RM WLAN Switch Configurations Signal Assignment DB9 male RS 422/485 Jumper Configuration LED Function SOHO Firewall Pass-Through IP Modem cable IP Modem Standard AT Commands IP Modem Extended AT-Commands IP Modem S-Registers for Configuration IP Modem Sample Dials IP Modem virtual Modulation IP Modem Responses IP Modem Information Responses IP Modem DTR Configuration April 2012 NetCom PRO User Manual 10

11 2 Introduction 1 Overview The NetCom PRO Serial Device Servers are designed to remotely operate serial ports over networks. The network interface is implemented as 100 Mbit/s Fast Ethernet with Auto-MDI(X). The subfamily of NetCom WLAN Serial Device Servers provide a second network interface as WLAN (as of g) with 54Mbit/s transfer rate. The transport is implemented via TCP/IP and UDP protocols. Therefore control is available via WLAN, Ethernet, Intranet and Internet. All communication with the NetCom PRO Servers may happen encrypted with strong algorithms on all interfaces. The supplied driver software implements virtual serial ports, which hide the network transfer from your applications. Software applications using standard COM ports need no change to operate via NetCom through the virtual serial ports. 2 Introduction This manual covers several different models of NetCom PRO devices, in particular the Wireless operating devices of the PRO series. In general the operation is the same on all models, except where explicitly noted otherwise. The devices come with a steel case well suited for industrial environments. The NetCom PRO supports high serial speeds up to 3.6 Mbps. All serial ports provide communication via the common RS 232 mode (up to 500 kbps). The NetCom PRO servers with a 13 in their name (and the PRO WLAN servers) also offer the industrial RS 422 and RS 485 configuration (up to 3.6 Mbps). In RS 485 mode the NetCom may use the Automatic Receive Transmit (ART) control logic to follow the RS 485 specifications for transmitting data. No special code is necessary to be implemented in your software applications. 2.1 About this Manual This manual covers many configuration options of the NetCom PRO Serial Device Servers. The vast majority of these are set by software, sometimes in alternative methods. To emphasize these in the text, special character styles are used. Bold Typewriter Typewriter is used for the names of configuration options or buttons, as they are displayed in menus or dialogs. denotes names of special values for multiple-choice parameters. Such values may appear in drop-down lists or as radio buttons. The version of the firmware described in this manual is 2.6.4, covered together with driver April 2012 NetCom PRO User Manual 11

12 2 Introduction 2.2 Features Single power supply DC 9-30V, AC V 47-63Hz, 25VA Wireless LAN b/g for 54Mbit/s on WLAN models Ethernet 10/100BaseTx/Auto-MDI(X) for auto-configuration Three way serial port interfaces: RS 232, RS 422 and RS 485 Max bps, half- and full-duplex TCP/IP configuration fixed or by DHCP Easy remote configuration via SNMP Drivers for Windows and Linux operating systems Documented interface for every networked operating system 2.3 Product Specifications Most of the hardware characteristics are common for all models. However some must differ from model to model, they are shown in dedicated sections. Some models are restricted to RS 232, others do not have a WLAN connection. April 2012 NetCom PRO User Manual 12

13 2 Introduction Common characteristics Processor ARM9 (KS8695P) Memory 16MB SDRAM 2MB Flash WLAN antenna SMA-reverse Ethernet connector RJ45 10BaseT/100BaseTx Protocols TCP/IP, UDP, SNMP, DHCP, ICMP, ARP, Telnet, RTelnet, HTTP Serial Speed 1 bps up to 3.69 Mbps 1 Parity None, Even, Odd, Mark, Space Data bits 5, 6, 7, 8 Stop bits 1, 2 (1.5 with 5 data bits) RS 232 TxD, RxD, RTS, CTS, DTR, DSR, DCD, RI, GND Serial signals RS 422 Tx+/Tx, Rx+/Rx,GND RS wire RS wire Data+/Data, GND Serial connector DB9 male (similar to PC) Serial operation RS 232, RS 422/485 configured by DIP switch or by software Management Serial console, Telnet, Web browser, SNMP Driver software Windows Vista/2003/XP/2000, Windows NT, Linux (Fixed TTY) Management software Driver installation and configuration program, Management console Operating temp. 0 to 55 C Approval CE, FCC Table 1: Specifications, common Note 1: Serial bitrates above 500 kbps may cause problems when used with RS 232. It requires short cables with low capacity, to reduce load on the serial signals. When using RS 422 or RS 485 there is no problem using maximum bitrates. April 2012 NetCom PRO User Manual 13

14 2 Introduction Device specific Characteristics NetCom 113 PRO One port. Power Requirement DC 9V to 30V, 300 Power Connector Terminal Block (3.6.1) Serial Ports 1 RS 232, RS 422/485 Dimensions mm3 (W D H) mm3 with connectors Weight 250 g Table 2: Characteristics of NetCom 113 PRO Figure 1: NetCom 113 PRO Top, Front and Rear Side This is the NetCom 113 PRO with the serial connector and the configuration switches. The rear side holds the power connector, Reset hole and the Ethernet RJ NetCom 411 PRO Four Ports. Power Requirement DC 9V to 30V, 400 ma@12v Power Connector Terminal Block (3.6.1) Serial Ports 4 RS 232 Dimensions mm3 (W D H) mm3 with connectors Weight 500 g Table 3: Characteristics of NetCom 411 PRO April 2012 NetCom PRO User Manual 14

15 2 Introduction Figure 2: NetCom 411 PRO Top and Front Side This is the NetCom 411 PRO with the serial connectors and the LEDs. The hidden rear side holds the power connector, Reset hole, the Ethernet RJ45 and the configuration switches NetCom 413 PRO Four Ports. Power Requirement DC 9V to 30V, 400 Power Connector Terminal Block (3.6.1) Serial Ports 4 RS 232, RS 422/485 Dimensions mm3 (W D H) mm3 with connectors Weight 500 g Table 4: Characteristics of NetCom 413 PRO Figure 3: NetCom 413 PRO Top and Front Side This is the NetCom 413 PRO with the serial connectors and the LEDs. The hidden rear side holds the power connector, Reset hole, the Ethernet RJ45 and the configuration switches. April 2012 NetCom PRO User Manual 15

16 2 Introduction NetCom 811 PRO Eight Ports. Power Requirement AC 100V to 240V, 47-63Hz, 25VA Power Connector Terminal Block (3.6.1) Serial Ports 8 RS 232 Dimensions mm3 (W D H) mm3 with connectors Weight 1350 g Table 5: Characteristics of NetCom 811 PRO Figure 4: NetCom 811 PRO This is the NetCom 811 PRO with the LEDs and the serial connectors. The rear side holds the power and the Ethernet connector as well as the Master configuration DIP switch. The Reset pin is located on the hidden right side. April 2012 NetCom PRO User Manual 16

17 2 Introduction NetCom 813RM PRO (19 ) Eight Ports. Power Requirement AC 100V to 240V, 47-63Hz, 25VA Power Connector AC Power plug (3.6.2) Serial Ports 8 RS 232, RS 422/485 Dimensions mm3 (W D H) mm3 with connectors Weight 1350 g Table 6: Characteristics of NetCom 813RM PRO Figure 5: NetCom 813RM PRO This is the NetCom 813RM PRO with the Ethernet connector and the LEDs, the serial connectors and the Reset pin (in the lower right). The brackets for 19 mounting shall be attached left and right to the case. This rack mount option is part of the shipment. The rear side holds the power connector and the Master configuration DIP switch NetCom 1611RM PRO (19") Sixteen Ports. Power Requirement AC 100V to 240V, 47-63Hz, 25VA Power Connector AC Power plug (3.6.2) Serial Ports 16 RS 232 Dimensions mm3 (W D H) mm3 with connectors Weight 1450 g Table 7: Characteristics of NetCom 1611RM PRO Figure 6: NetCom 1611RM PRO Front side April 2012 NetCom PRO User Manual 17

18 2 Introduction This is the NetCom 1611RM PRO with the Ethernet connector and the LEDs, the 16 serial connectors and the Reset pin (in the lower right corner). The hidden rear side holds the power connector and the Master configuration DIP switch. Not shown here are the mounting angles for a 19 rack NetCom 1613RM PRO (19") Sixteen Ports. Power Requirement AC 100V to 240V, 47-63Hz, 25VA Power Connector AC Power plug (3.6.2) Serial Ports 16 RS 232, RS 422/485 Dimensions mm3 (W D H) mm3 with connectors Weight 1450 g Table 8: Characteristics of NetCom 1613RM PRO Figure 7: NetCom 1611RM PRO Front side This is the NetCom 1613RM PRO with the Ethernet connector and the LEDs, the 16 serial connectors and the Reset pin (in the lower right corner). The hidden rear side holds the power connector and the Master configuration DIP switch. Not shown here are the mounting angles for a 19 rack. April 2012 NetCom PRO User Manual 18

19 2 Introduction NetCom 123 WLAN One Port. Power Requirement DC 9V to 30V, 300 Power Connector Terminal Block (3.6.1) Serial Ports 1 RS 232, RS 422/485 Dimensions mm3 (W D H) mm3 with connectors Weight 250 g Table 9: Characteristics of NetCom 123 WLAN Figure 8: NetCom 123 WLAN Top and Front Side Here showing NetCom 123 WLAN with the antenna, the serial connector and the configuration switches. The hidden rear side holds the power connector, Reset hole and the Ethernet RJ45. April 2012 NetCom PRO User Manual 19

20 2 Introduction NetCom 423 WLAN Four Ports. Power Requirement DC 9V to 30V, 400 Power Connector Terminal Block (3.6.1) Serial Ports 4 RS 232, RS 422/485 Dimensions mm3 (W D H) mm3 with connectors Weight 500 g Table 10: Characteristics of NetCom 423 WLAN Figure 9: NetCom 423 WLAN Top and Front Side Here showing NetCom 423 WLAN with the antenna, the serial connectors and the LEDs. The hidden rear side holds the power connector, Reset hole, the Ethernet RJ45 and the configuration switches. April 2012 NetCom PRO User Manual 20

21 2 Introduction NetCom 823RM WLAN (19") Eight Ports. Power Requirement AC 100V to 240V, 47-63Hz, 25VA Power Connector AC Power plug (3.6.2) Serial Ports 8 RS 232, RS 422/485 Dimensions mm3 (W D H) mm3 with connectors Weight 1350 g Table 11: Characteristics of NetCom 823RM WLAN Figure 10: NetCom 823RM WLAN Front Side Here showing NetCom 823RM WLAN with the Ethernet connector and the LEDs, the serial connectors and the Reset pin (in the lower right). Also visible is the WLAN antenna from the rear side. Figure 11: NetCom 823RM WLAN Rear Side The rear side holds the power connector and the Master configuration DIP switch. This image also shows the front side with the 19" mounting angles. This rack mount option is part of the shipment. April 2012 NetCom PRO User Manual 21

22 2 Introduction 2.4 Packing List NetCom PRO or NetCom WLAN Serial Device Server Power supply 12V 1A for DC Models NetCom 113 PRO, 123 WLAN, 411 & 413 PRO, 423 WLAN and 811 PRO Power cord for AC Models NetCom 813RM PRO, 823RM WLAN, 1611RM PRO and 1613RM PRO WLAN Antenna for NetCom WLAN Models Mounting angles for 19 models CD-ROM with driver and configuration software Quick Installation Guide April 2012 NetCom PRO User Manual 22

23 3 Hardware Description 3 Hardware Description This section focuses on the options provided by the hardware of NetCom PRO Serial Device Servers 3.1 Serial Port Configuration The serial ports in the NetCom Devices follow the specifications of RS 232. It is also possible to use the serial port in RS 422 or RS 485 mode. This is defined by a set of DIP switches or by software. Here is a list of the available modes and the switch settings. Warning: a bad configuration may cause serious damage in the NetCom or the connected device. Line Mode, Comment S1 S2 S3 S4 Switch Positions RS 232 Configuration via serial port Off Off Off Off RS 232 Data communication Off Off On On RS 422 Data communication Off On On On RS 485 by ART 4 wire Full Duplex On On On Off 2 wire Half Duplex with Echo On On Off On 2 wire Half Duplex no Echo On On Off Off RS 485 by RTS 4 wire Full Duplex On Off On Off 2 wire Half Duplex with Echo On Off Off On 2 wire Half Duplex no Echo On Off Off Off Selected by Software Off On Off Off Factory settings Off Off Off On Table 12: Switch Configurations Configuration via serial port is only effective on port 1 of the NetCom Server. ART is the Automatic Receive Transmit control. In RS 485 this is the recommended option. The NetCom performs the required activation and disabling of the RS 485 transmitter by an internal automatic. April 2012 NetCom PRO User Manual 23

24 3 Hardware Description The Master DIP switches configure all serial ports of a NetCom to the same operation mode. If different modes are desired, the switch must be set to «Selected by Software», and the configuration may be done via Serial Port, Telnet, Web browser or SNMP. Factory Settings are restored on next Power-Up/Reset of the NetCom Server. 3.2 Signal Assignment It is of course important to know the exact location of the serial signals in the configured mode. Here is the table for the DB9 male connector. For RS 232 the assignment is the same as on any PC (Com1/2). Pin RS 232 RS 422/485 4-wire RS wire 1 DCD Tx (A) Data (A) 2 RxD Tx+ (B) Data+ (B) 3 TxD Rx+ (B) 4 DTR Rx (A) 5 GND GND GND 6 DSR 7 RTS 8 CTS 9 RI Figure 12: Connector DB9 male Table 13: Signal Assignment DB9 male Please note the GND signal in RS 422 and RS 485 modes. This signal must also be connected between the serial devices. So in reality there is neither a 2-wire nor a 4-wire connection. With the exception of very special configurations, a serial cable without GND violates the specifications for RS 422 and RS RS 422/485 Electrical Configuration In typical RS 422 and RS 485 installations certain electric conditions have to be configured. Simply connecting cables is not enough to fulfill the specifications or RS 422 and RS 485. For ease of installations the NetCom PRO Serial Device Servers provide these functions for often used parameters. They are activated by placing certain jumpers, internal of the NetCom PRO. There is one block of jumpers near each serial port. Place a connection cap to activate the function. April 2012 NetCom PRO User Manual 24

25 3 Hardware Description Pins Function of Signals 1-2 Place 120Ω to terminate Tx± (Data± in RS wire) Add BIASing function to Tx± (mostly required for RS wire modes) 7-8 Place 120Ω to terminate Rx± Add BIASing function to Rx± Table 14: RS 422/485 Jumper Configuration Figure 13: RS 422/485 Option Jumper Warning: All jumpers are unconnected by default. This is important for use in RS 232 mode. Never close any jumper, otherwise communication errors or damage of devices is possible Termination Resistors The use of long communication lines in RS 422 and RS 485 mode require the installation of termination resistors. These must match the impedance of the cable. Typical cables in Twisted-Pair configuration have an impedance of about 120Ω. In RS 422 this resistor has to be placed at the far end from the sender, in RS 485 the typical configuration requires one resistor at each end of the cable BIAS Function RS 485 requires a BIAS option for the communication lines. This will guarantee stable electrical levels on the cables, even at times when no station is transmitting data. Without BIAS there will be noise on the cable, and sometimes receivers can not detect the first characters of a beginning communication. 3.4 Serial Port Simple Settings There is one set of 4 Dip switches to configure the operation mode of the NetCom PRO Device. This switch is the Master configuration for each serial port. All ports operate in the same mode, unless the DIP switches configure for software setting. Before connecting a serial device, the serial port configuration must be completed. Warning: a bad configuration may cause serious damage in the NetCom or the connected device. To avoid these problems, it is recommended not to connect a device to the serial ports in the first installation. The serial ports should be configured for RS 232. This is done by setting the DIP switches like this example. Figure 14: Master Switch Standard Configuration April 2012 NetCom PRO User Manual 25

26 3 Hardware Description 3.5 Network The NetCom PRO connects to Ethernet, while the NetCom WLAN may use either WLAN or Ethernet at customers choice. By factory settings both interfaces are enabled, and the priority is set for Ethernet (i.e. via cable). If no cable is connected here, the Wireless interface is active. Otherwise the server communicates via Ethernet. Both interfaces use the same MAC Address and IP Address, to allow for seamless fail-over from cable to wireless operation. The NetCom WLAN Servers do not perform a DHCP request when the WLAN interface becomes active WLAN Configuration The pre-defined operation mode is ad-hoc, which means you do not need an Access Point to get access to the NetCom. Any computer with WLAN equipment may contact the NetCom WLAN. The configuration of the NetCom WLAN is done with the tools described later. This is the most easy way of installation. However the Ad-hoc mode is not encrypted by definition of the IEEE standard. As one result any station can read the data transferred to the NetCom WLAN. This also includes the passwords. Further in case of problems, it is harder to find the source of the problems. Therefore the recommended method is to use the Ethernet connector for the first configuration. Or in case of doubt, use the first serial port to configure the NetCom. The configuration of the WLAN parameters should follow in a later step. This is especially the case, if encryption or certain other parameters require special configuration WLAN Antenna The connector used for the WLAN Antenna is known as SMA-Reverse. This is a standard type to allow for simple connection of different equipment. Just fit the supplied antenna by carefully screwing it to the connector. You are free to connect a cable and a different antenna of your choice, as long as it is designed for WLAN. When the NetCom WLAN detects an operational WLAN it can connect to, the Blue LED lights Ethernet The connector for Ethernet is the usual RJ45. Simply connect it to your (switching) Hub. Because the Ethernet has Auto-MDI(X) function, a direct cable or a cross-over cable may both be used. When the connect is done the Link LED on NetCom PRO (yellow) will light. When data traffic occurs on the network, this LED will blink. It depends on your network whether a 100Mbit or a 10Mbit connect will be established. A 100Mbit net causes the Speed LED on NetCom PRO (green) to light, otherwise it will remain dark. April 2012 NetCom PRO User Manual 26

27 3 Hardware Description Red LED Yellow LED Green LED Status Off Device off, no power On Off Off No connection On On Off 10Mbit connection established On Blink Off 10Mbit data transfer (traffic) On On On 100Mbit connection established On Blink On 100Mbit data transfer (traffic) Table 15: LED Function 3.6 Power Supply The NetCom PRO device is powered by a single 9-30V power supply. It requires 200 ma up to 1500 ma of current, depending on the device type and voltage supplied. A suitable power supply adapter is part of the packaging. Connect the cable to the power jack (Terminal Block) at the rear side of NetCom PRO, and put the adapter into the socket. You may connect a power supply of your choice, providing the technical requirements are met. For the 19" devices of course just plug the power cord into the socket, the NetCom accepts 100V to 240V AC, 47 to 62Hz. The Power LED on NetCom (red) will light Terminal Block Power The Terminal Block power connector receives positive voltage on the right (V+) pin. The center (V-) pin connector is negative, which is connected to GND and the case. GND is the same as Field GND (FG), so the standard adapter does not connect to this pin. Figure 15: Power Terminal Block AC Power Plug AC power is provided by a standard cable. Protective Earth connects to the case. Figure 16: AC Power input April 2012 NetCom PRO User Manual 27

28 4 Windows Virtual COM Driver 4 Windows Virtual COM Driver This chapter covers the use of NetCom Devices via Virtual Com Ports installed by the supplied driver software for Windows. Sections 4.1 to 4.3 describe in details the process of driver installation and removal, as well as updating. This first part here is for quick installation, so only the common options are covered. Section 4.4 provides the details of NetCom Manager and also the options available with the Virtual Com Ports. 4.1 Installation Procedure Before starting installation, it is essential to have an IP configuration ready for the NetCom Device to install. You may read the TCP/IP Description (section 11) below. The default configuration is based on DHCP, which is fine in many networks. If in doubt, please ask your Network Administrator for help. Further it is assumed the network access is functional. It is recommended to use Ethernet via Hub or Cross-Over cable for configuration. The following description is based on Windows XP Professional, with Service Pack 2 installed. The installation on other configurations of Windows is similar. The installation of drivers is described first. This is followed by a procedure to verify a correct installation. The last part of this section is about the uninstall or update processes of drivers and tools. Drivers are provided for Windows NT, Windows 2000 up to Windows 7, Windows Server 2000 up to 2008 R2. The x86 and x64 Editions have separate drivers. The drivers use the IP Address of NetCom Servers to operate. So the configuration of the device should avoid to change that over time. This is either done via a static IP Address, or by proper configuration of the DHCP server. In the second case the DHCP server shall recognize the NetCom by its MAC Address, and assign the same IP Address each time the device sends a request. All available DHCP Server products provide such a function, even in SOHO routers Start the Installation Wizard This is the Installation Wizard, it is named VSNSETUP.EXE ab. You ll find it on the CD-ROM shipped with the NetCom PRO, in the directory responsible for your operating system. The drivers are also available on the Internet, in the latest version. Start this program to install the drivers. Figure 17: Installation Wizard a VSNSETUPA64.EXE in x64 Editions of Vista and Windows XP b VSNSTUNT.EXE in Windows NT April 2012 NetCom PRO User Manual 28

29 4 Windows Virtual COM Driver Figure 18: NetCom Driver Installation The installation program offers three different ways of installation. The first option is the most common used function, a Complete Installation. All driver files and tools are copied to the Windows system, and installed in the Start Menu. Further the drivers are installed in the system, and the network is searched for available NetCom. The serial ports on these devices are installed as Virtual Com Ports in the system. The second option will Install Tools and Drivers. However the network is not searched for Net- Com Devices. And of course no serial ports are installed in the system. This function is designed to prepare a computer for use of NetCom Virtual Com Ports, but the final installation shall be skipped for some reasons. For example the computer shall be shipped to a customer, and the final installation shall happen there. Finally the third option is to Install Tools only, no drivers. At time of writing these tools are the NetCom Manager, as well as the uninstall and repair functions. This function should be selected when the use of Virtual Com Port drivers is not intended. The NetCom Devices may be used in many different operation modes covered later (6). There are also some Hyperlinks, opening access to more recent driver versions. This part of the manual documents the Complete Installation, so click this option. April 2012 NetCom PRO User Manual 29

30 4 Windows Virtual COM Driver Figure 19: Start Driver Installation A target folder for a file copy is requested. The tools and driver files are installed here. The tools will appear in the Start Menu, so a sub-folder of your Program Files is suggested. Just click the OK button. Figure 20: Copy Driver Files Some files are copied to your hard disk, this is the usual process similar to other Windows installations. The upper bar increases with the progress of each step performed in the installation process. The lower bar illustrates each step performed until full installation is finished. April 2012 NetCom PRO User Manual 30

31 4 Windows Virtual COM Driver Find and Configure NetCom Devices When all files are copied, the NetCom Manager 1 program is started. This searches for all NetCom Devices on your network. Figure 21: Discover and Select NetCom Devices for Installation After short time the search process is finished. All discovered NetCom are listed. In your very first installation of NetCom Devices and Drivers you should connect only one NetCom to your network. This single Device is listed here. Identify it by comparing the serial number shown in the NetCom Manager. Figure 22: NetCom in Manager Configure IP Parameters As mentioned above, it is important to configure the NetCom to operate in your network. In many networks this is done by a special server (DHCP). Please ask your Network Administrator for information. If you need to define parameters manually, doubleclick the devices icon. 1 This program is covered in detail in 4.4. For now follow the minimum steps. April 2012 NetCom PRO User Manual 31

32 4 Windows Virtual COM Driver Figure 23: Define NetComs IP Configuration This panel opens. Deselect the Option of Use DHCP, and place your parameters as IP address, Netmask and Broadcast. Click on the OK button. Since driver version you may also enter a DNS name instead of the IP Address. Figure 24: DNS Name for NetCom Server Click the DNS button, and enter the Qualified Domain Name defining the NetCom Server. Your Administrator will provide you with it. This name is translated to an IP Address and used by the driver. When all parameters of the configuration are set, click the OK button. This will update the configuration of the NetCom, the new parameters are sent to the device. April 2012 NetCom PRO User Manual 32

33 4 Windows Virtual COM Driver Figure 25: Sending Parameters to a NetCom Configure Firewall As you will notice in figure 23 the driver may also operate by traversal of a Network Firewall. This requires a special configuration, which is skipped here. Please read in detail in section 5.6 on page 54. For now proceed with the standard installation Install Drivers You are now back in the NetCom Manager. Click the OK button, the installation continues. Windows detects the serial ports on the fresh NetCom as new Hardware. All new Virtual Com Ports are installed without manual intervention by the user. Figure 26: Virtual Com Ports installing However using early driver versions or certain configurations of Windows, the system may request certain actions by the user. You may be asked about to get latest drivers. April 2012 NetCom PRO User Manual 33

34 4 Windows Virtual COM Driver Figure 27: New Hardware Wizard Automatic searching of Windows Update website will take quite a long time. So select the third item, and click on Next. This question neither appears on Windows XP prior to SP2, nor on any previous Windows version. April 2012 NetCom PRO User Manual 34

35 4 Windows Virtual COM Driver Figure 28: Install drivers for the serial ports The pre-selected automatic installation is fine, just click on Next. The driver files are already copied to your hard disk. Now Windows installs them in the system directory. To Finish the installation click on that button as it appears. If the system can not detect the drivers, use the second option. Add the folder as given in figure 19 to the search, then the system will detect suitable driver files. These latest steps happen for each serial port on the NetCom Device. Just repeat the procedure, until all ports are successfully installed. Windows will show you this. In most situations it is not required to reboot the system. Of course you can do that now, to test the drivers. 4.2 Verify the Installation In the Start Menu you ll find the new program group "VScom NetCom". The installed programs are the NetCom Manager, the Driver Repair program and an option for uninstallation. This group is not installed on Windows NT. Figure 29: VScom drivers in the Start Menu April 2012 NetCom PRO User Manual 35

36 4 Windows Virtual COM Driver Figure 30: NetCom in Device Manager In the Device Manager the serial ports are listed in the usual section Ports. Additionally there is the device class Multi-port serial adapters a. All installed NetCom Devices are listed herein. The available options are described later. On Windows NT there is no Device Manager. You ll find the serial ports listed in the Control panel in the Ports applet. To configure the NetCom and special port options, there is a new applet named NetCom Manager. Figure 31: NetCom Manager NT a In drivers up to version this was VScom Virtual Com 4.3 Update the Drivers and Tools As suggested by figure 43 the Installation Wizard offers an option to Update the drivers to a new version. Windows itself also offers an option to update the drivers of installed devices. Although this is a functional option, the correct operation of the NetCom drivers depends on a common version for all drivers. The secure way to perform such an update is to run the Installation Wizard. All driver files are replaced by later versions simultaneously, and all configuration data (Com number, special port configurations,...) is preserved. Because several internal configurations of drivers have changed from version to 1.5.8, the option of Update is not available in this situation. The only way of update is to Uninstall the current version, and install the new. Such a situation will be very rare. 4.4 Configuration of the Virtual COM Driver If properly configured, the serial ports of the NetCom Devices appear as Virtual Com Ports in your computer. The "virtual" means, in the computer is no real hardware related to the serial port, April 2012 NetCom PRO User Manual 36

37 4 Windows Virtual COM Driver however the driver offers the full functionality of a serial port to the system. The interface used by the driver is VCOMM, which in turn is supported by the Windows API. So Windows does not see a difference to Com1, and also no application should detect the change. When the serial ports are installed by the Virtual Com driver software, any application may use them. In the Device Manager they appear as NetCom COM Port (figure 30). Without special tests a program does not see a difference between Com1 and the virtual Com7. For example the Hyper Terminal program has no problem to communicate through these Virtual Com. And this situation is common amongst most programs Configure the Serial Ports A typical application selects a serial port, and opens it. After that it performs the standard configuration of bits per character, parity settings and number of stop bits. Also the flow control (handshaking) is defined by the application. Windows sends these requests to the port driver, and this driver sends the requests to the serial port on the NetCom. Figure 32: NetCom COM Port Serial Settings The same parameters may be pre-configured in the Device Manager. This is done via the Properties of the NetCom COM Port. In the Local Settings tab these standard parameters are defined. Since most programs configure these parameters by themselves, the values are very rarely used. A typical situation is a serial printer attached to this virtual port. April 2012 NetCom PRO User Manual 37

38 4 Windows Virtual COM Driver As usual this behaves different in Windows NT. There is no Device Manager. To change these standard parameters, open the Ports applet in the Control Panel. However it is suggested you open the new NetCom Manager applet instead. Change to the Ports view as in figure 38. Doubleclick on the small icon at the left side. In this dialog go to the Local Settings tab, as seen above Performance Issues Operation through the network causes some extra time, which is approximately 5 Milliseconds. For comparison, with a port internal to the computer this time may be just some 100 Microseconds. This added time has an impact on reaction times. Some data protocols may be sensible. A lot of configurations are possible to compensate for this. But these have an effect on the sheer data throughput of the virtual serial port. Figure 33: NetCom COM Port Performance Settings Consequently the configuration starts on the Performance tab. There are four already defined sets of parameters. Best Performance is the default configuration. The driver software and the NetCom communicate with big data blocks. As a result a reaction on short events on the serial port is somehow delayed. For applications operating with short data blocks, and waiting April 2012 NetCom PRO User Manual 38

39 4 Windows Virtual COM Driver for short answers this is not optimal. It causes transmission delays, called Latency. Good Performance uses smaller blocks. The Latency may be reduced a little bit, depending on the application. But the impact on the data throughput is small. Short Latency mimics a 16C550 with full FIFO enabled, but no network timeouts will occur. This means the block size is 16, quite small for network operations. Virtual FIFO Off simulates a deactivated FIFO, which is the fastest setting in terms of latency. The port is configured as if the FIFO is off, buffers are configured to never wait for a timeout, hence gaining in best reaction times. The FIFO buffers are not deactivated in reality, they are still used to prevent data loss. Driver Defaults returns to the standard settings when enabled. Advanced opens access to detailed configuration of the operation parameters. April 2012 NetCom PRO User Manual 39

40 4 Windows Virtual COM Driver Network & Misc Properties When you use the Advanced checkbox on the Performance tab, the Network/Misc tab opens automatically. Figure 34: NetCom COM Port Network/Misc Properties The parameters on this tab control the operation of the driver software on the computer. Tx Network Buffer Size: If the application sends small chunks of data to the driver, these are buffered to send them in one large packet. This parameter defines the size of the buffer. And also the maximum packet size sent to the serial port by the driver software. Rx Network Buffer Size: This is the size of the buffer to receive data from the NetCom. Automatic Trigger: based on internal rules, this checkbox selects a best practice value for Tx Trigger Level. Deactivate it to control that parameter manually. Tx Trigger Level: Controls the time when data is sent to the NetCom. If the Tx buffer holds at least this amount of data, the driver April 2012 NetCom PRO User Manual 40

41 4 Windows Virtual COM Driver immediately sends them. If there is less data, the driver may use a timeout to determine when to send them. Network Timeout (ms): This is the timeout. Overspeed: This is a special option, not really related to network communication. There are old applications, limited in the maximum speed. With Overspeed you define a multiplier. The baudrate requested by the application is multiplied with this factor. The result is sent to the NetCom to configure the serial port. E.g. the application may be limited to 38,400 bps, but there is a modem capable of 230,400 bps on the serial port. Set Overspeed to a value of 6.000, and configure the application to use 38,400 bps. Open If Absent: The NetCom may be used from a computer with a Dial- Up connection. When this option is used, the driver will delay the connection to NetComs serial port. Even when an application opens the port and configures the parameters, no command is sent. The connection is established when data is sent to the NetCom, or when status information is requested. Keep Alive: This option will periodically send control information to the NetCom to check if the connection is still operational. As a second effect a Dial-Up connection will not automatically close. Passive Modem: This option controls how often the driver retrieves Modem status information from the NetCom. If activated, the driver never asks for the modem status. Instead the NetCom informs the driver of any changes. If an application frequently requests the Modem status, it gets the last value received. On slow networks like the Internet this option is recommended. If inactive, the driver software retrieves the Modem status from the NetCom serial port each time the application requests it, but with a maximum frequency of 10 per second. If the latest retrieved information is not older than 100 milliseconds, this value is returned. Simulate Device Off on Connection Loss: When this option is enabled, the NetCom driver does not attempt to preserve transmitted data. If on a normal serial port the connected device is switched off, all data sent to this device gets lost. NetCom simulates this behavior. All data sent from the application to the driver is discarded, when the TCP connection to the Net- Com is lost. The NetCom driver attempts to re-establish the connection in regular intervals. When the NetCom is available again, data may be transferred from then on. April 2012 NetCom PRO User Manual 41

42 4 Windows Virtual COM Driver Remote Settings Properties The other panel created by activating the Advanced checkbox on the Performance tab, is the Remote Settings tab. Figure 35: NetCom COM Port Remote Settings Properties The parameters on this tab control the operation of the serial port on the NetCom Device. They are defined and activated by the driver software. Tx Trigger Level: The serial port on the NetCom Device buffers data for transmission to external devices. If the amount of data in this buffer drops below this level, the NetCom is capable to receive new data. It will send a related event to the driver software. Rx Trigger Level: When the serial port has received this amount of data, these are sent to the driver on the connected computer. If the amount is less than this, the NetCom applies a timeout of about 5 character times. This means the timeout varies with the serial transmission speed. The Remote Flow Control panel signals the NetCom to perform the handshake on its own. This is necessary, because the network delay of some milliseconds is to long for reliable operation in many situations. April 2012 NetCom PRO User Manual 42

43 4 Windows Virtual COM Driver Enable: The configuration shown here is active, when the pre-defined performance levels are used. When using the Advanced option, Remote Flow Control is completely disabled. Enable as required. While it is best practice to configure as figure 35, you can disable certain events here. CTS, DSR, Tx XON/XOFF: these control the output of data to the serial port. RTS, DTR, Rx XON/XOFF: used to stop transmission from the connected device. An application has the option to use any combination of these methods at the same time. The command to use them is transferred to the NetCom. For example, if the port is configured to use Hardware Flow Control, the NetCom will control the RTS line, and observe the CTS line. If requested, any of these methods may be unchecked. In that case the driver software on the computer will control the lines. Override App Settings: In rare situations it is necessary to ignore the applications configuration. Check this box, and select the Flow Control functions to use with the device. Limits: These buttons are prepared for future software versions. April 2012 NetCom PRO User Manual 43

44 4 Windows Virtual COM Driver Installation of NetCom Servers This section of the manual covers the correct installation of the drivers and serial ports. Please do a quick review of the section 4.1, before reading further. As of the time of writing, the current driver is version Figure 36: Select NetCom to install The NetCom Manager program is started by the Installation Wizard. Often there are more than only one NetCom listed. And sometimes not all of them are to be used on this specific computer. The Exclude button is used for that purpose. Select a NetCom Device, and click on that button. The driver will later ignore this NetCom, when installing and operating the serial ports. The Icon changes to olive color. In figure 36 above you ll notice yellow questions marks at each icon. These appear when the NetCom is not already installed for the Virtual Com driver. It may also appear, if you open NetCom Manager without Figure 37: Excluded NetCom administrative privileges. If the mark changes to a red exclamation mark, the NetCom is non functional. It may be without power, the network may be broken, or the device is completely removed. Or the NetCom Manager is still without administrative privileges. To clear the display in NetCom Manager just select that NetCom and use the Remove button. April 2012 NetCom PRO User Manual 44

45 4 Windows Virtual COM Driver If a NetCom has not been operational when the Manager program was started, it is either displayed with the exclamation mark, or not displayed at all. You may make it operational by connecting it now. To install it, use the button Search to find it in the network. Or Add it manually with that button (section 5.6). Figure 38: NetCom Manager Ports View Similarly you may exclude certain ports on a specific NetCom Server from installation as a Virtual Com port. These are the special options used while installing the driver software. At any time after installation the configuration may be changed by the NetCom Manager program. This may result in serial ports appearing in or vanishing from the system Changing the Installation There are common situations, when the current configuration needs a change. In the first case the NetCom has been moved to a different location, or the logical structure of the network has changed. It may happen the IP Address of NetCom is also changed. Either by Automatic (DHCP), or manually via a different interface like the Web browser. Because of the changed address the driver does not find the serial port to contact. Figure 39: Reconfigured NetCom found Now open the NetCom Manager. It will re-detect the devices. In this process the Manager finds the already installed NetCom, but with a new configuration. Then the Manager requests interaction from the user. This question here assumes the NetCom shall be installed from scratch. This will produce a Com port with a new number. If just a reconfiguration has occurred, click on No. When April 2012 NetCom PRO User Manual 45

46 4 Windows Virtual COM Driver you do that, the parameters of the installed Virtual Com Port are changed to contact the same serial ports on a new network address. Figure 40: Replaced NetCom found The second case occurs, when a NetCom is replaced by another device. This new device shall have the same configuration, especially the same IP Address. When you start the NetCom Manager, it will detect a new device with parameters already in the database. So a similar question appears. An installation of a new serial port is assumed again. If the device shall replace the old one, click on the No button. In general the driver software and the NetCom Manager identify the NetCom Devices by the combination of IP Address and serial number. If one of these is changed, the above requests appear. 4.5 Uninstall the Drivers and Tools To completely uninstall the NetCom Drivers and files, there are three methods. The usual way is to use the Add/Remove Programs applet in the Control Panel, and remove the NetCom Drivers. This will start the NetCom uninstallation program. Figure 41: Uninstall NetCom Drivers via Control Panel April 2012 NetCom PRO User Manual 46

47 4 Windows Virtual COM Driver As a second way you may start the Uninstall program in the start menu. The third method is to start the Installation Wizard again from CD-ROM or the installation directory. The Wizard will detect the drivers on the system. You have the options to Repair the current installation, or to Remove the installed drivers. Since the Installation Wizard is of the same version as the installed drivers, the option of Update is not available. Figure 42: Uninstall NetCom Drivers in Start Menu Figure 43: Remove, Repair A Repair replaces the driver files on the system with those in the installation package. Since this is the same versions, the files should also be the same. If anything is damaged in the installed drivers, the Repair process will correct the problems. As expected the Remove process will uninstall drivers and tools from the system. The drivers are removed from the configuration and also completely deleted from the System drive. This happens with any configuration data also. Afterward the system is available for a clean installation. April 2012 NetCom PRO User Manual 47

48 5 Configure with NetCom Manager 5 Configure with NetCom Manager Shipped with the NetCom Devices there is a versatile program for Windows Operating System, named NetCom Manager. This program shall detect, manage and configure the NetCom Devices in your network. You can start it by several ways. First of all it is stored on the CD-ROM, named NETCOMMGR.EXE 23. It is possible to start it directly from the CD-ROM. See this Icon. When the Virtual Com Drivers are installed, there are more options to run the program. In Windows NT the same Icon appears in the Control Panel, to start the NetCom Manager program. Also the process of installing the drivers created a new program group in the Start Menu. Figure 44: NetCom Manager This section of documentation focuses on management of the NetCom Devices. The options to configure driver-specific parameters of the serial ports are skipped here. This includes some buttons and panels. They are described in total in section 4.4, in the documentation of the drivers and panels. While in the configuration process, a click on a button or a double-click on an item opens properties or other options. In many situations, a right-click with the mouse opens contextsensitive options. Just try it out. The NetCom Manager is designed to help configure driver options. So for very detailed configuration of a Figure 45: NetCom Manager in Start Menu NetCom, it is better to use the Web browser interface, or do it via Telnet as described in section 6. Here are the options. 2 NETCOMMGRA64.EXE in x64 Editions of Windows 3 NETCOMMGRNT.EXE on Windows NT April 2012 NetCom PRO User Manual 48

49 5 Configure with NetCom Manager 5.1 Starting NetCom Manager When NetCom Manager is started, it will Search the NetCom in your LAN by SNMP. This process may take up to 30 seconds. The devices in a LAN are typically found in the first seconds. If this is enough for you, you can stop the search by click on the Done button. Figure 46: NetCom Manager Servers Panel The NetCom are listed here in the Servers panel. Since the Search uses broadcast mechanisms, the range is limited. If you have Routers in your network, or you contact some NetCom via Internet, you must Add them manually (section 5.6). Enter the network parameters to access the NetCom. Select a NetCom, and click on the Properties button, double-click the Icon, or use a right click. Using Verify the NetCom Manager contacts the NetCom to check if it is properly configured and online. Exclude is only useful in conjunction with the Virtual Com Drivers, so skipped here. Search repeats the search from the program start, and may be used at any time. Remove removes a NetCom server from this list. This option is most often used to clear old data from the drivers database. For monitoring purposes you may select a NetCom, and Start Log for this. It may be done for several Devices at the same time. The output is visible in the Log Windows panel. April 2012 NetCom PRO User Manual 49

50 5 Configure with NetCom Manager 5.2 NetCom Server Settings Info As described above, open the Properties of a NetCom Device. The Server Settings start with the Info panel. Configure the options as your network requires. Figure 47: NetCom Manager Server Settings - Info The Server Name is just for information. As factory setting it includes the serial number of the device. You may change it to any string (of ASCII characters), since there is no functionality related to the name. This name is listed in the Server panel of NetCom Manager. The next parameters are fixed, and displayed for information only. The Telnet port allows to configure this NetCom via Telnet. The value is a TCP port number. Factory setting is 23, the standard port for Telnet protocol. By default the NetCom is set to Use DHCP for automatic configuration of IP parameters. This is the suggested method. However there are several situations where this option can not be used. In this case deactivate it. When inactive, other parameters may be changed. The basic parameters IP address and Netmask are mandatory. Instead of an IP Address you may enter a DNS name. The NetCom Manager will resolve that name to the actual IP Address. If address or netmask are changed, the NetCom Manager calculates a matching address for Broadcast. You may also change this address. The DHCP option will also configure the Default gateway and the Name server. Without DHCP you must enter these parameters by yourself, enter if they are not used. April 2012 NetCom PRO User Manual 50

51 5 Configure with NetCom Manager 5.3 NetCom Server Settings Ports The Ports panel lists all serial ports of a NetCom. Some of the options are driver related, e.g. the Com Number. Each serial port may operate via two TCP ports. Figure 48: NetCom Manager Server Settings - Ports The TCP Control Port is used in the Virtual Com Driver mode, and also in Null-Modem Tunnel. If Driver mode is not desired, this parameter is ignored almost always. The TCP Data Port is used to transmit data to and from the serial port. Use the default, or change the value to the settings required for your network. There is also a UDP Data Port, used in packet data transfer. You can not switch the NetCom to UDP mode with the Manager. But if it is already in this mode, you can change this basic parameter. April 2012 NetCom PRO User Manual 51

52 5 Configure with NetCom Manager 5.4 NetCom Server Settings Firewall Many networks use a Firewall to protect the stations in the network from other networks, including the Internet. In some situations the contact to a NetCom must pass through such a Firewall configured for NAT (Network Address Translation, section 13). Figure 49: NetCom Manager Server Settings - Firewall To do this you must Enable Firewall, and enter the Address of the Firewall. The address may be the IP Address, or the Qualified Domain Name (DNS). The Manager configures a NetCom via SNMP, which uses UDP. The Firewall must have a special Port to receive those data, and to transfer it to the internal network. Enter this port here. The same scheme applies to the logging option. When logging is active a NetCom listens on port 1200 for logging connections. The Firewall must also have a special Log Port to receive this connection, and to transfer it to the NetCom. The NetCom does not need any configuration to operate in a Firewall protected environment. This configuration here is for installation of the drivers. There is a Firewall tutorial section later in this manual (5.7). April 2012 NetCom PRO User Manual 52

53 5 Configure with NetCom Manager 5.5 NetCom Server Settings Options Figure 50: NetCom Manager Server Settings - Options This Panel is available since software version , in this enhanced version. A Safe to File of the configuration is available, as well as the opposing Load from File of this data. But this function is dedicated for the most basic parameters only. It is highly recommend to use the option to Save and Load the configuration via the Web Browser (paragraph on page 101). You can also Reboot the NetCom. This may be useful, e.g. if an old connection blocks access to the NetCom. The button Apply Changes commits all parameter settings done so far to the NetCom. And the Verify checks the current settings by reloading the status from the NetCom to the Manager program. When you want to install a Firmware Update, use this button. But this option is designed for old firmware versions. It may operate with your device, it is still available for compatibility. But it is highly recommended to use the option via the Web Browser (paragraph on page 101). The NetCom may be protected for access, in this case you must place the current Server Password in the dialog. The option to change the password is reserved for a future extension. Exclude Server is related to the Driver installation only. April 2012 NetCom PRO User Manual 53

54 5 Configure with NetCom Manager You may Enable Log to see events at the NetCom, for monitoring. If enabled, the log will also appear in the central Log Window. At any time it s possible to Clear the log, or Capture the data to a file. 5.6 Manual Detection/Installation of a NetCom Sometimes the NetCom Device Server can not be detected by the automatic in the NetCom Manager. To detect and configure devices the protocol SNMP is used. The detection is done by sending out a broadcast on all available network interfaces of your computer. This SNMP broadcast is realized as an Ethernet broadcast. Such a broadcast is only transmitted through Hubs and Switches. When there is a Router between the computer and the NetCom, probably the broadcast is not transmitted further. This is especially the situation when the NetCom is located somewhere via Internet, but also in big networks of some companies. If this is the case, the detection has to be done manually. Refer to figure 36 and Add the NetCom by use of the button. Enter the IP Address of the NetCom in the NetCom Manager Server Settings, and click the button Verify. Since now the IP Address of the NetCom is known, the NetCom Manager sends a request directly to this target, instead of a broadcast. This directed SNMP request is transported, even by Routers. The NetCom sends the normal reply, giving all required information to the NetCom Manager. Now it is possible to configure all options as usual. Also the drivers for virtual serial ports are installable now. Please note, the drivers require to have the IP Address. They can not operate using a DNS name, because the driver can not perform a DNS name resolution. If your NetCom is located on a dynamic IP Address (e.g. on a Dial-Up connection with 24 hours disconnection), you need to reconfigure the driver installation, when the IP Address has changed. There is a NetCom Helper Service 5.8 for assistance. 5.7 Firewall Traversal Configuration There are more difficult situations with a Firewall between the NetCom and the NetCom Manager. Many Firewalls protect the internal LAN by using the feature of NAT (Network Address Translation, 13). In this situation the IP Address of the internal device is not visible on the Internet. Only the Firewall can be contacted via its public IP Address. The NetCom Manager and the driver software for the virtual serial ports can handle such setups. But this requires certain configurations. An easy-to-use alternative is provided with the NetCom PRO models. This implements a VPN to the NetCom PRO, which makes Firewall configuration quite easy SOHO Firewall example The most easy situation for such a setup is by using a very simple SOHO Router as the Firewall. This configuration will show the principle of the technical details. Those principles can be transferred very easy to the configuration of more complicated installations. On the SOHO Router there is only one public IP Address on the external side, and typically 254 internal private IP Addresses for the LAN side. These internal addresses may be assigned by DHCP or static. Such Routers offer a feature typically named "DMZ", which in fact is only a single exposed April 2012 NetCom PRO User Manual 54

55 5 Configure with NetCom Manager host. It is recommended not to use the "DMZ" for several reasons, some of them are security related. Especially it is recommended not to configure a NetCom as the DMZ host SOHO Virtual Servers The Router also offers "Virtual Servers" (here named ViServ for short), which is the option required for NetCom installation. These ViServ operate by a technique called PAT (Port Address Translation, 13). Certain data addressed to the public IP Address of the Router are forwarded to the internal private address of the NetCom. This way the NetCom can be contacted via the public IP Address of the Router. First you need to configure the Router for some ViServs. As the absolute minimum there is one ViServ for the NetCom device itself, and another two ViServs for each serial port of the NetCom. Those ViServs are to be configured for TCP or UDP transmissions. Please read in the manual of your Router how to do that. You need a port for the external interface, and an IP Address plus a port for the LAN side. The LAN IP Address is of course that of the NetCom. As an example the most easy device is a NetCom 113 PRO. The internal port for SNMP is 161 for UDP. The serial port requires ports 2000 and 2001 for TCP. Function External port Internal port SNMP 8161/UDP 161/UDP Control 9000/TCP 2000/TCP Data 9001/TCP 2001/TCP Table 16: SOHO Firewall Pass-Through Configure your Router for these example ViServs, and use the internal IP Address of the NetCom for the targets. Connect the NetCom to your LAN. Now you are ready for a very first test. Use Telnet to connect to the Data port of the NetCom serial port. Open a console (DOS Box) and type the command Telnet <Routers-IP-Address> 9001 You will be connected to the serial port. Every character you type is sent out of the serial port, and every received data is shown on your screen. The serial parameters are pre-configured in your NetCom NetCom Detection through SOHO Firewall Now open the NetCom Manager as in section 5.6 above, and click the Add button. You again get the NetCom Manager Server Settings dialog. But now you have to select the panel named Firewall (see figure 49). Check the Option Enable Firewall, and enter the IP Address of the Router in the Address field. In the field Port enter the target port for the SNMP configuration. From the Virtual Server example above this is port Since there is no configured ViServ for Logging, ignore this field. Click the button Verify to have the NetCom Manager contact the Router. This is a directed request, so there is no problem with broadcasts. The Router will transfer the request to UDP-Port 161 on the NetCom, which is the port for SNMP. The NetCom will answer the request, and send it out to April 2012 NetCom PRO User Manual 55

56 5 Configure with NetCom Manager your computer. The NAT function in the Router will replace the source IP of the data by its own public value, so the NetCom Manager will see the answer come from the Router. The NetCom Manager is satisfied with this data. Some ISP will block the SNMP protocol, which typically means they do not transport data for 161/udp to their customers (this is the first reason why port 8161 was used in the example). This answer brings every required information about the NetCom, including its internal IP Address. Select the panel of NetCom Manager Server Settings to verify the information, but do not make any changes here. Changing the configuration may disconnect the NetCom from the protected LAN Serial Ports through SOHO Firewall Now the NetCom is available in the NetCom Manager, but still the serial ports are not usable. The information of the TCP-ports for the ViServ related to the serial port is still missing. In the NetCom Manager Server Settings select the NetCom Manager Ports Panel. In this panel select one serial port, in this example of NetCom 113 PRO there is only one serial port. Click the Properties button to open the configuration of the port. Figure 51: NetCom Manager Port Configuration for Driver Since the Firewall function is enabled, the parameters for Firewall mapping are available for editing. Enter the ports defined in the Router, 9001 and 9000 in this example. Please note, so far there is no number for the Virtual Com Port available. The driver is not installed in this April 2012 NetCom PRO User Manual 56

57 5 Configure with NetCom Manager moment, and Windows does not know about the available hardware. This will happen later in the installation. Click the OK button, and proceed with the driver installation as already described DMZ and Virtual Servers Why is it recommended not to use the DMZ function of the Router? There are two reasons. The first one is simple, only one device in the LAN can be defined as the DMZ target. The DMZ is implemented as "Send all IP data targeted for the Router to the DMZ station, unless there is a specific rule for a different target". When a second NetCom shall be installed on the LAN, the Virtual Servers have to be configured anyway. The second reason is the security. Using the DMZ option the Firewall in the Router becomes transparent. All data from outside is transferred to the LAN, including all malicious data. In general this is not an especially smart idea. 5.8 NetCom Helper Service In certain situations users of VScom NetCom Serial Device Servers come to the problem of dynamic IP Addresses. This typically happens when the NetCom is used over Internet, using an ADSL or cable Modem connection. At certain times (e.g. every 24 hours) the NetCom is disconnected from the Internet. When it is re-connected, it will receive a new IP Address, which is different than before. The NetCom Driver for Windows installs the serial ports on the NetCom Servers as virtual local Com Ports in the system. They are seen in the Device Manager, and standard applications like Hyper Terminal have a seamless access to the connected serial devices. To perform this task the driver uses the IP Address of the NetCom Server. On the established TCP connections the driver exchanges serial data, commands and status information. When the IP Address of the NetCom has changed, the driver attempts to contact the old IP Address, which will fail. So the virtual Com Port is not usable any longer. Up to driver version users have to use the NetCom Manager to reconfigure the driver. Since the driver version there are more options. The software installs a so-called Helper Service on the system. This service monitors the configured NetCom Servers, and detects the changed IP Address. The driver is reconfigured to use the new IP Address, so the port is usable again. This all happens without specific user interaction Configure Helper Service The NetCom Helper Service is configured via NetCom Manager. There is a new Register card. In the upper part users Enable the Helper Service, and they also configure the Polling Period (i.e. frequency). If the Helper Service is disabled, it is also stopped in the system; it does not consume any system resources. Of course it does not provide any help when disabled. The Polling Period is given in seconds. When the interval has passed, the configuration of the NetCom Servers is checked. April 2012 NetCom PRO User Manual 57

58 5 Configure with NetCom Manager Figure 52: NetCom Helper Service The lower part in the new panel lists all NetCom Servers available in the system configuration. The user must decide which of those shall be monitored (Enable). At the regular intervals as configured above the NetCom Server is checked. The Helper Service attempts to connect to the NetCom Server, and verifies the parameters. If the verification fails, the Service uses several methods to find and identify the NetCom Server Detection and Priority The NetCom Helper Service has two basic methods to detect and identify a NetCom Server. The first method is the broadcast search on the network, the new method is DNS based. The DNS method has two variants, with or without firewall configuration. The reasons for changing IP Addresses or the methods to use are discussed later Broadcast Search The method of broadcast search is the same method as used in the NetCom Manager. A broadcast request is sent to the local network, and the NetCom Servers reply to this. The NetCom Manager lists them for configuration. This method is used by the NetCom Helper Service also. A NetCom Server is identified by MAC- Address and Serial Number. These two parameters are fixed, customers can not change them. If a NetCom Server is found with a changed IP Address, the driver configuration is updated DNS based Search In driver versions up to the NetCom Server has been configured by its IP Address. This is still the standard situation in later driver versions. However the Info Panel of Server Properties is modified (see figure 47). You may enter a Qualified Domain Name instead of the IP Address. Figure 53: Enter Qualified Domain Name The name is resolved, i.e. translated to the current IP Address associated with the name. This IP Address is configured in the driver, and the DNS name is also saved there. April 2012 NetCom PRO User Manual 58

59 5 Configure with NetCom Manager In a local company network this may not be an especially useful option. But when the NetCom Server is used via the Internet, this is the standard situation for most applications. DNS is used when the NetCom is not a part of the local network broadcast domain. As a consequence it is not detectable via the broadcast method described above. Provided there is a reliable DNS service available, now it is more easy to install a NetCom in the system. Please read about the Manual Detection/Installation of a NetCom in section 5.6. The NetCom Helper Service regularly checks if the NetCom Server is still available on the known IP Address. If the attempt for contact fails, the Helper Service uses DNS to find the new IP Address of the NetCom Server. This new IP Address is used for future operation DNS based Firewall Configuration The NetCom Servers do not manage an Internet Connection on their own. But it is possible to have a NetCom Server on a public IP Address, when the Internet Connection is managed by Routers. More often the NetCom Server connects to a private LAN, and has a private IP Address. The Internet Connection is managed by a Router, which also acts as a Firewall. This Router uses NAT/PAT to make the NetCom Server available via Internet. Please read about this in section 5.7. When the Firewall Configuration is activated for access to the NetCom, it has been possible to enter the DNS name of the NetCom Server in previous versions of the driver. Precisely it was the DNS name of the Router. This name has been resolved at the time of configuration, and has been stored for later use. Now the NetCom Helper Service monitors the DNS name to connect to the NetCom Server. If the connect fails, the DNS name is resolved again. The new result is used in the driver. The driver can again contact the firewall to get access to the NetCom and the serial ports Changed IP Address There are several configurations with changed or regularly changing IP Addresses. This is a rough overview Broadcast Domain The broadcast domain is part of a local network. In typical SOHO networks the domain covers the entire network. The broadcast domain is typically limited by Routers. Broadcasts are transmitted between computer and NetCom Server, if there are only Switches/Hubs or WLAN Access Points on the way between those two. Usually the IP Addresses in a local network are static. This is also the situation when there is a DHCP server, and all clients use this. If the server is configured properly, it will provide the same IP Address to a certain station again and again. It does so, because the stations are identified by their unique MAC-Address. A changed IP Address may occur because the network is re-organized, combined with a reconfiguration of the DHCP server. In most cases however it is simply because the station has been switched off for a comparably long time. So the DHCP server forgot about the station, and provided the IP Address to a different target. April 2012 NetCom PRO User Manual 59

60 5 Configure with NetCom Manager Internal DNS If the company network becomes larger, it will also use some Routers. For organization the network is grouped in subnets. As mentioned above, typically the broadcasts are blocked by Routers, so the broadcasts only cover a single subnet. To contact stations in other subnets the IP Address of the target is required. Usually this is provided by a DNS server. This server may co-operate with a DHCP server. A usual cause for a changed IP Address in the NetCom Server is a connection to a different subnet. It will have a different IP Address there, but the DNS server should know about the new address Internet Some ISP disconnect the customers stations from the Internet in regular intervals, e.g. every 24 hours. If the station is configured for immediate re-connect, it will get a new IP Address. This station can notify a Dynamic DNS service, so this will resolve to the new address. This is typically combined with a SOHO Firewall/Router Polling Period The last matter to check about is a suitable Polling Period for the NetCom Helper Service. The standard value is 3600 seconds, i.e. one hour. With this configuration a change in the address is noticed up to 60 minutes later. When the change occurs just before the Helper Service checks the connect, it will be recognized very soon, if the check happens just after the change, it will require the maximum time. Usually an installation requires to have changes detected very soon, but this is not possible on networks. The NetCom Server has no feature to contact all clients, and notify them of a changed configuration. This is because the NetCom Server can not manage a possibly huge list of client computers. So the Helper Service is installed on the client computers. If there are a lot of clients, very frequent polls cause a high load. For one side on the network, but most important on the NetCom Server. The best choice for a suitable polling interval depends on the usage period of the client computer. If it is unused for some hours per day (over night), it will detect a change at least the next morning. Provided the change happens over night. If the NetCom Server uses an Internet connection with regular disconnects, it is a good idea to configure those disconnects to times of inactivity of the clients. For manual detection of changes it is possible to restart the NetCom Helper Service. Controlling a service requires administrative privileges on the Windows system. A restricted user account can not do this. Restricted users use the Polling Period configured by the system Administrator. April 2012 NetCom PRO User Manual 60

61 5 Configure with NetCom Manager 5.9 Dynamic IP Address and OpenVPN Since Firmware version 2.2 there is a different method to provide a tunnel to the NetCom. The option of Encryption uses a Virtual Private Network (VPN) based on a single TCP connection between the NetCom and a client computer. Regardless of strong encryption or even weak as not encrypted, here the key point is the single TCP connection. It is more simple to provide a Firewall configuration for a single connection, so the Router Firewall is more easy to set up. The network link established by OpenVPN requires to have a target address and a port number. Since the basic TCP connection is activated by the openvpn.exe program, there is the freedom of using a DNS name for the target device. With a Dynamic IP Address for the NetCom site, one of the several Internet services for Dynamic DNS (DDNS) may help. It is even relatively simple to construct an own version. Using this service the openvpn.exe program gets the IP Address of the Firewall Router, and will establish the link. When the IP Address changes (after 24 hours), the connection first gets lost. OpenVPN will continuously attempt to connect again. When the new IP Address is known via DDNS, the network link is re-established. The NetCom is available again, because the IP Address on the OpenVPN link did not change. Even when a serial port has been open, the function will continue seamlessly. April 2012 NetCom PRO User Manual 61

62 6 Configure the Operation Modes 6 Configure the Operation Modes The NetCom Devices are often used without the installation of a driver software. Customer applications contact the NetCom directly, using network functions. These setups require independent configuration of the NetCom Device and the serial ports. There are five ways to do this configuration. The NetCom offers a Web browser interface, configuration via serial port, via Telnet and also via SNMP. This SNMP option is not covered in this manual, please see separate documentation. The NetCom Manager program for Windows is already explained above. The access to the NetCom via web interface or Telnet are done via a TCP/IP connection between the computer and the NetCom. So users need the IP Address of the NetCom. The most easy way to retrieve this information is the NetCom Manager program (section 5). Start it, and open the Info Panel (figure 47) of the NetCom Server you want to configure. This panel displays the current IP Address of the NetCom. Do not change the parameters, just write down the value. The default configuration of a NetCom is for use of a DHCP server. When such is not available, the IP Address defaults to When the IP Address of the NetCom is not in final state, leave the NetCom Manager open while doing the first configuration of the NetCom Server. But in general the software may be closed as soon as the IP Address is known. 6.1 Accessing the Configurations Here the manual shortly explains the different methods to get access on the parameters of a NetCom. These parameters are the same, independent from the method for configuration. So the options are described later. The configuration is accessible via web browser, a Telnet software with VT100/VT52 emulation, or via a Terminal emulation connected to the first serial port of the NetCom Web Browser Configuration Open your favorite web browser, and enter the IP Address as the target location. To avoid any confusion you should precede it with so your browser has definite target information. Most browser programs do not need that. Your browser must not suppress images. If the NetCom is password protected, you must enter this now. Leave the user name empty, just type the password. April 2012 NetCom PRO User Manual 62

63 6 Configure the Operation Modes Figure 54: Configuration Menu in Web Browser The NetCom welcomes you with its "Home" screen. To access the different options of configuration, the images above function as a link. In many menus you ll see a blue question mark. This is a symbol for help. When clicked a short explanation pops up, informing about the function of this parameter. Some other settings require a reboot to save and activate them. Whenever this situation occurs, the NetCom requests a REBOOT. Figure 55: Request to Reboot in Web Browser It is done like this here, you may reboot then, or do that later when the configuration is finished Telnet Configuration Start your Telnet software with the IP Address of the NetCom as the parameter. In most configurations you use the standard port for Telnet, so you omit this parameter. As an example this is the command-line in Windows, which you may enter in Start Run, or in a console (DOS box). C:\Windows\System32>Telnet April 2012 NetCom PRO User Manual 63

64 6 Configure the Operation Modes For completeness the port is shown in this command. Enter the configured parameter when the port is different. If the NetCom is password protected, you need to enter the password right now. Please enter your password: Figure 56: Password Request in Telnet When connected to NetCom you must define the type of terminal used. Most Telnet software includes an emulation of a VT100 terminal, so choose this option. Also choose this option for an ANSI emulation. Please choose your terminal type (1:VT100 2:VT52 [1]): 1 Figure 57: Select Terminal Type in Telnet The configuration with Telnet is menu-driven NetCom WLAN V ServerConfig SerialPorts Tools Save&Exit h=help -+ Server configuration settings Figure 58: Main Menu of Configuration Console in Telnet This is the start point for configuration. ServerConfig has all options to configure the NetCom device itself, including the IP-Parameters to access it. SerialPorts defines settings related to the serial port. Tools has some utilities like PING or displays statistics. In Exit you may leave the menu or reboot the NetCom. At any time you can get a short hint by typing "H" for help. April 2012 NetCom PRO User Manual 64

65 6 Configure the Operation Modes Use the cursor keys to select the parameter you want to change. Hit <Enter> to edit them. Type the new value, or select provided options. Use <Esc> to leave a parameter or menu. Please check the configuration of your Telnet, if there are any problems Serial Configuration In some situations it may be impossible to get network access to the NetCom Device. If this happens (e.g. by an accidentally misconfiguration), neither Telnet, nor the web interface is functional. It may be even impossible to use the NetCom Manager program. In this case you must connect to the NetCom via the serial port. Disconnect any serial cable from NetCom. Set the DIP Switches to "RS 232 Configuration" (all switches to Off, section 3.1). Then connect the NetCom with your computer using a Null Modem cable. If your NetCom is an old model with a connector DB9 female, attach the supplied Null-Modem Adapter to the port first. Or connect your computer to the female connector with a straight-through cable. Open any serial terminal program (Hyper Terminal, minicom, PuTTY 4,... ), select bps, 8 Bit, No Parity as configuration. Set your terminal to emulate a VT100 (recommended, but VT52 is also possible), including the Arrow keys. Then power on the NetCom. When connected to NetCom you must define the type of terminal used (VT100 or VT52), and optionally provide the password. This is the same configuration option as described above at 6.1.2, so follow the instructions for Telnet. When the configuration is done, change the DIP Switches back to normal operation. Later configurations can be done by web interface or Telnet. Of course this requires to have a functional IP configuration defined. 6.2 NetCom Configuration Options Some of the menus are very long, especially on the web interface. These are divided in their logical sections throughout this document. Each section shortly mentions the way to access the parameters. Short screen shots show the typical display when configuring the NetCom. Usually the web interface is shown on top, and the terminal interface (Telnet, serial port) is shown below; a horizontal line divides the two. On few occasions the two screen shots are displayed side by side, with the web interface to the left and the terminal interface to the right; then divided by a vertical bar Server Configuration In your web browser click on the Icon of SERVER CONFIGURATION, the browser opens the basic server information, the server parameters related to the IP-configuration, the parameters for Wireless communication, the section for encrypted communication, Password settings, and finally the configuration for date and time. In Telnet the ServerConfig offers the IP parameters, Wireless and encrypted configuration, Password settings, configuration for date and time, as well as basic server information. 4 Download PuTTY from putty.org April 2012 NetCom PRO User Manual 65

66 6 Configure the Operation Modes Server Info Web: menu SERVER CONFIGURATION, section Server Info. Telnet: ServerConfig, option Info ServerConfig Parameter Wireless OpenVPN Authentification Date & Time Info Server Info Server Type 423 WLAN Software Version Hardware Version 1.0 Serial Nr UpTime 3 day(s) 02:10:17 Contact [<unset> ] Location [<unset> ] Figure 59: Server Information Information about the selected NetCom is displayed as Server Info. Starting with the Server Type, this is the model of the NetCom, followed by the Software Version and Hardware Version. This will give a rough overview, which features are implemented, or need an upgrade of the firmware. The Serial Nr. is important to identify the device you are configuring right now. For further information the UpTime is listed. Contact and Location are user-defined information. They may later help to find the device in the installation, and the person responsible for management. The Administrator may provide some contact information here. Contact defines a person to contact for help, e.g. "Mrs. Jane Doe, 555-HELP". Location is the physical place of the NetCom, e.g. "CeBIT Hall 12, Service Box IX.a". These data are restricted to ASCII characters. April 2012 NetCom PRO User Manual 66

67 6 Configure the Operation Modes Server Parameter Web: menu SERVER CONFIGURATION, section Server Parameter. Telnet: ServerConfig, option Parameter The Server Parameter allow configuration of the NetComs name and of course all parameters in IP-settings. The Server Name is used as general information, e.g. in the NetCom Manager program. On a NetCom WLAN you may choose the network Interface Priority as Cable, Wireless or both (priority Cable,Wireless or Wireless,Cable). Figure 60: Server Parameter Web Interface April 2012 NetCom PRO User Manual 67

68 6 Configure the Operation Modes ServerConfig Parameter Wireless OpenVPN Authentification Date & Time Info Server Parameter Server Name [NetCom_ ] MAC Address 00:04:D9:80:00:14 Options auto Interface Priority Cable, Wireless DHCP Enabled IP Address Netmask Broadcast Gateway DNS Domain netcom.vscom.com.tw ConfigPort [23 ] PrintServerPort [515 ] KeepAlive Off KeepAliveInterval [0 ] Figure 61: Server Parameter Telnet Interface The Options first implemented in firmware version define the operation mode of the Ethernet Interface. The details are explained below. Manual changes of IP parameters are only available with DHCP set as Disabled. When DHCP is not used, enter IP Address and Netmask, as well as the Broadcast address. Gateway is required, if there are Routers in the network. DNS is used to access other stations by name. The ConfigPort is used to access the NetCom for administration via Telnet. It is suggested to use the standard value for Telnet, TCP port number 23. However it may be changed for different purposes. This does not change the function of the Telnet menus. Firmware version 2.2 introduces the new function as Print Server. The TCP Port defined by RFC1194 (mostly referred to as»line Printer Daemon«) is 515, under certain circumstances you may change the PrintServerPort. More about Print Server function at the configuration of the serial ports ( on page 91). KeepAlive is an intrinsic function of the TCP/IP protocol. If used it causes network traffic, traditionally intended to prohibit automatic shut-down of Dial-Up network equipment. In a LAN this traffic usually is not a problem. If this functions is On, you must define a KeepAliveInterval given in seconds. As a side effect of the traffic network problems are detected earlier. NetCom has a better chance to react on network problems, or failed hosts. Even dropping an old connection may be useful in certain environments. It is suggested to activate this function when using RAW TCP communication ( , ), with an interval of about 180 seconds. April 2012 NetCom PRO User Manual 68

69 6 Configure the Operation Modes The Options for Ethernet allow to control the network operation mode by configuration, overriding the automatic negotiation of the hardware auto filtered 100 fd 100 hd 10 fd 10 hd Figure 62: Ethernet Operation by Software auto is the standard operation. The Ethernet port automatically detects the capabilities of the connected device, and adjusts to the best possible communication. filtered is not recommended. Useful in certain networks, activate on explicit instruction. 100 fd configures for communication at 100 Mbit/s in Full Duplex mode. This is best possible, and usually configured without special configuration. 100 hd configures for communication at 100 Mbit/s in Half Duplex mode. Normally not advised, used if the automatic detection fails. 10 fd configures for slow communication at 10 Mbit/s in Full Duplex mode. For connection to old network hardware, if this is not detected. 10 hd configures for slow communication at 10 Mbit/s in Half Duplex mode. For connection to very old network hardware, like Thin or Yellow cable. Not recommended. April 2012 NetCom PRO User Manual 69

70 6 Configure the Operation Modes Wireless Parameter Web: menu SERVER CONFIGURATION, section Wireless Parameter. Telnet: ServerConfig, option Wireless This section is of course only available on the NetCom WLAN class of devices. To operate a Wireless device, a lot of parameters are required. The configuration in the NetCom is reduced to a small set of them, for ease of configuration. ServerConfig Parameter Wireless OpenVPN Authentification Date & Time Info Chipset Ralink RT2561T SSID [NetCom_ ] OperationMode Ad-hoc WirelessMode 11 b+g CountryRegion ETSI (1-13) Channel 7 Encryption Type Off Encryption Key [empty] RTSThreshold [2312] FragmentationThreshold [2312] Figure 63: Wireless Parameter The Chipset is provided as a read-only parameter. This defines the hardware base for the WLAN functions. The first models of NetCom WLAN used the RT2560. Current models are equipped with RT2561T, which provides the additional WPA2 encryption. Later models may have different hardware, possibly providing more WLAN functions. SSID is the «Service Set Identifier». This is used to get access to radio cells established by an Access Point. By default it is used as identification in Ad-hoc mode, and built from the serial number. This means it is the same as the default NetComs name. The OperationMode is selectable as Ad-hoc for a direct connection from wireless stations to other stations, and also as infra to select the «Infrastructure Mode». The second mode is required to connect to an Access Point. Other wireless stations such as a PC or Laptop use the Access Point to transfer the data to the NetCom. April 2012 NetCom PRO User Manual 70

71 6 Configure the Operation Modes The WirelessMode is available as 11b and 11b+g. It may be necessary to use the restriction of 11b when compatibility problems with other clients occur. WLAN as of IEEE b/g defines fourteen possible channels (i.e. predefined frequencies) to use with WLAN devices. Some of these frequencies are restricted in some countries. Please check with your local regulations for the channels you are entitled to use. This manual is just informative, it is in no way a reproduction of local regulations. The available CountryRegion values are FCC(1-11) for North America, ETSI(1-13) for Europe in general, SPAIN(10-11), FRANCE(10-13) and MKK(14) in Japan. Late information indicate even in Spain and France the full range of ETSI is now legal; check yourself. In Infrastructure Mode the NetCom adapts to the configuration of the Access Point. Be sure to have the correct Country/Region to match the parameters of the Access Point. The Access Point must broadcast the SSID, otherwise the NetCom will not contact it. The Channel is used in Ad-hoc mode. Depending on the Country Region the selection is restricted. In Infrastructure Mode this value is defined by the Access Point. Encryption Type defines the encryption of the radio transmission. WPA-PSK/TKIP or WPA2. It may be Off, WEP, ServerConfig Off WEP WPA-PSK/TKIP WPA Figure 64: Wireless Encryption Modes The WEP encryption may use 40 or 104 bit keys, sometimes also named WEP40/64 or WEP104/128. Which of this is required is defined by the Encryption Key Parameter. This key may be entered as ASCII characters, or as hexadecimal for a binary key. A string with 5 characters results in WEP40 using an ASCII key. Using 10 characters as key defines this key as also WEP40, but with a binary key in hexadecimal notation. Likewise a 13 character string is WEP104 with ASCII, and 26 characters select WEP104 with a binary key. WPA Encryption is available using TKIP cypher. The key is PSK (a Pre-Shared Key) and must be installed on all stations. An ASCII key consists of 8 to 63 characters, a binary key are 32 bytes in hexadecimal (64 characters) notation. WPA2 Encryption is provided in firmware version 2.6, the cypher is AES. The key is similar as with WPA, i.e. 8 to 63 characters, or 32 bytes. It is recommended to use WPA/WPA2 with a binary key, generated from random data. As with all encryption options a strong key is required for protection on page 75 provides a little help and background information. RTSThreshold and FragmentationThreshold are low level WLAN parameters. They should match the configuration in the Access Point. Higher values result in better data throughput. But when transmission errors occur, the impact is dramatic. In this case lower values provide better security and better performance. The configured values shall match those configured in the Access Point Encrypted Communication Web: menu SERVER CONFIGURATION, section OpenVPN Parameter. Telnet: ServerConfig, option OpenVPN April 2012 NetCom PRO User Manual 71

72 6 Configure the Operation Modes Firmware version 2.2 introduces a way for encrypted communication with the NetCom PRO Serial Device Server. This function establishes an encrypted VPN tunnel between your computer and the NetCom. All communication to the NetCom uses this new connection. No application requires a change of operation or source code, but seamlessly gets the advantages of Encryption. This may be especially useful to get secure communication via an otherwise insecure Wireless LAN. To build this tunnel NetCom uses the Open Source product OpenVPN ( This section is about the configuration of the parameters on the NetCom side. The function and the configuration of OpenVPN is described with more details later in section 9 on page 121 of OpenVPN Client installation. ServerConfig Parameter Wireless OpenVPN Authentification Date & Time Info OpenVPN Disabled TCP Port [1194 ] IP Address [ ] Netmask [ ] Broadcast [ ] Max.Clients [8] Cmd.Line Params (Server) [ ] TCP Port (Destination) [1194 ] IP Address (Destination) [ ] Cmd.Line Params (Client) [ ] Encryption None Logging Off [ Generate Key ] [ Upload Key ] [ Stored Key ] Figure 65: OpenVPN Network Parameter April 2012 NetCom PRO User Manual 72

73 6 Configure the Operation Modes Of course OpenVPN may be Disabled, active as Server or in the combined Server-Client mode. When the function is active, the NetCom is virtually invisible on the IP Address defined in Server Parameter ( ). It will still answer on ICMP, and also the Logging function is available for trouble shooting. But there is only one connection accepted by the NetCom, to the TCP Port defined for OpenVPN. Nothing more is available for security reasons. The IP Address is the local address on the VPN, it should be a private address (RFC 1918). This VPN also has a Netmask and a Broadcast address, this is similar to the configuration of the "Server Parameter". The Limit of Max.Clients specifies how many stations may establish simultaneous connections to the NetCom; it does not limit the number of installed clients. The field of Cmd.Line Params (Server) is available since Firmware version 2.6.2, and accepts commandline parameters to openvpn in server mode. Users with deep knowledge about openvpn may add special configuration here, The content is not checked by the firmware, so check many times for avoiding a malfunction. If OpenVPN is configured for Server-Client mode, it will establish a connection to a given Server, e.g. another NetCom PRO. The TCP Port and the IP Address of the Destination are required. The field of Cmd.Line Params (Client) is available since Firmware version 2.6.2, and accepts commandline parameters to openvpn in client mode. Users with deep knowledge about openvpn may add special configuration here, The content is not checked by the firmware, so check many times for avoiding a malfunction. If Logging is On, NetCom sends the messages of OpenVPN to the standard debug log output None AES-128-CBC AES-192-CBC AES-256-CBC Figure 66: OpenVPN Encryption grades Different grades of Encryption are available, from no encryption at all to AES with a 256 bit key. Select the required grade of security, and open the Configuration-Settings of the Encryption-Key to open a window for the parameters. The management of encryption keys behaves different in a web browser or by Telnet. Figure 67: OpenVPN Key Management in Web Browser April 2012 NetCom PRO User Manual 73

74 6 Configure the Operation Modes This window is for key management. The NetCom allows to Generate a new key from Pseudo Random Data. This key is displayed in the browser window. Depending on the configuration of your Web browser, it will attempt to immediately save the key to a file on your disc. Since the Internet Explorer also shows this behavior, the Firmware suggests a file extension of ".cfg" instead of ".key". Windows may react crazy on "key"-files. Please also note, this fresh new key is only displayed/saved. The configuration of the NetCom has not changed. To use this new key on the NetCom, you must load it to the NetCom. Select the file containing the key data, and Upload it to the NetCom. This may be any key, regardless of the source. Instead of loading a new key to the NetCom, it is possible to Show the key currently used. Again some browsers including Internet Explorer directly attempt to save the key. The Telnet menu (figure??) provides three Options for key management. Generate a new key from Random Data 5, it is displayed in the terminal window. Depending on your terminal program, you need to have the logging capability active to save the data, or on other programs you may directly save the screen content. Here is a sample key displayed. # Please copy this key into a new text file BEGIN OpenVPN Static key V f3fc3d7d1d22d5b3ba1e498d27338c7 f8bf452edf484fae209d657b8cabfc58 9d2edb0c84eae68a65d6e93cda dbf8a7c38a73c9bc5f1a1ce0e0e b297945d6e0482a84f2397ab5ba8e f0e41b8ab4a511d42ca6405c 8348f40652d e8c0bcfc4c2b91 0ee7772be2b54ed0c0574acd9643d3b5 05a260ed54bd3ba730d12863b4f3df5a 4207b90562c6c7a9c27febabf6e0aa69 ebd eed159c48a94a3da4a30e 7411c4ca2fca8afa365c535877dc00a5 306ddab341b0bf5b325be68b849294a5 47b69cc493aaf f b8964caf707b ea4b955d8f97263c233d280e032ba83e -----END OpenVPN Static key V Figure 68: Sample OpenVPN Key in Telnet Please note, this fresh new key is on the display only. The configuration of the NetCom has not changed. When you exit this display with the <ESC> key, you are asked whether you want this key as the new key in your NetCom Should the generated key be stored as your new secret key? Yes No Figure 69: Use new Key in Telnet 5 Actually from a PRNG (Pseudo Random Number Generator) April 2012 NetCom PRO User Manual 74

75 6 Configure the Operation Modes Select Yes to use this new key on the NetCom. As an alternative you may Upload any key to the NetCom, regardless of the source. This way you have your Telnet/Terminal software to send the key as an ASCII file. Check your documentation on how to do it. With Hyper Terminal you may just paste the text into the window. Instead of loading a new key to the NetCom, it is also possible to Show the key currently stored on the NetCom Generating strong keys As seen the OpenVPN function allows to generate a new key on the NetCom. The result may be used to get a new binary key for Wireless and other Encryption. Just generate the key, but do not store it. Copy 64 (26/10) hexadecimal characters from the middle area, and place them on one line. This is at least better as typing something on the keyboard. Binary random data has 8 random bits per byte. In contrast ASCII characters only have 7 bits, but these aren t pure random. Only 94 characters from ASCII are printable, but usually they are not selected by random. Playing monkey on the keyboard generates a small set of characters. This is equivalent to 4 random bits per character, or even less. Selecting every 11 th bit from a given text may look better, but also this is not random Authentication Web: menu SERVER CONFIGURATION, section Authentication. Telnet: ServerConfig, option Authentication ServerConfig Parameter Wireless OpenVPN Authentification Date & Time Info Security Settings Password [empty] PPP Server Authentication Accounts [name:pass,name2:pass2 ] Figure 70: Access Authentification The Security Settings define a Password to restrict access to the configuration of NetCom. The password is not shown while typing it. To protect against accidental mistyping, you must type the Password twice. April 2012 NetCom PRO User Manual 75

76 6 Configure the Operation Modes The "PPP Server Authentication" provides a list of Accounts, which are usable to Dial-In to the NetCom. For background information about this feature please consult section 10. The list consists of accounts, separated by comma. Each account is a pair of username and password, separated by a colon. This list is valid for all serial ports Date & Time Web: menu SERVER CONFIGURATION, section Date and Time Settings. Telnet: ServerConfig, option Date & Time It may be helpful to have a correct time setting in the NetCom. You may manually enter the time here. Please note, there is no real time clock with a battery backup in the NetCom. When the NetCom is restarted, the time is lost. Retype the value of Date & Time for manual setting. The format is DD-MM-YYYY HH:MM:SS UTC+/-TZ (Time Zone). ServerConfig Parameter Wireless OpenVPN Authentification Date & Time Info Date and Time Settings Date & Time [ :17:33 UTC+0] Simple Network Time Protocol State Off Mode DHCP Interval [1800 ] Server [ ] Figure 71: Date & Time Retrieval Options It is possible to configure NetCom for automatic time retrieval via SNTP. The State field has three possible settings: Off: disables automatic time retrieval. Startup: NetCom gets the time at reset or power on. Interval: NetCom repeats to retrieve time. April 2012 NetCom PRO User Manual 76

77 6 Configure the Operation Modes The parameter Mode is used to find the definition of the Time Server. It may be defined direct, or by DHCP 6. The Interval in seconds instructs the NetCom to regularly check for an update of the internal time settings. The Time Server may be given by IP Address or by name. A name of course requires a configured DNS server Save Web: menu SERVER CONFIGURATION, at bottom. At the bottom of the web page below all the options there is the button Save. This will store all configurations done here in the NetCom. Selecting a different configuration section from the menu may discard all changes done. For many configuration changes the NetCom requires a reboot to proceed, especially if the IP parameters have been updated. The Telnet section has a separate menu for saving configurations, described later. 6 DHCP has to be active in the Server Parameter see at Server Parameter April 2012 NetCom PRO User Manual 77

78 6 Configure the Operation Modes Serial Port Configuration In your web browser click on the Icon of SERIAL CONFIGURATION. This is a huge menu in the web browser. Each serial port of the NetCom is listed in a separate Column. A maximum of four serial ports is shown. Select the appropriate group of ports. Figure 72: Port Page Selection in Web Browser The top half of the parameters titled Serial Settings is directly related to common serial configurations. The bottom half titled Transfer Settings configures the operation mode of NetCom on the network. Each serial port is configured separately, there is no setting shared between ports. In the Telnet menu select SerialPorts in the Main Menu, and directly select the serial port to configure. The settings available in this menu are by port. Therefore, first the port to configure has to be chosen. SerialPorts Port 1 Port 2 Port 3 Port SerialPorts Serial Settings Transfer Settings Figure 73: Port Selection in Telnet Just select the port by placing the cursor, and then press <Enter>. The next option is to configure the Serial Settings or the Transfer Settings. April 2012 NetCom PRO User Manual 78

79 6 Configure the Operation Modes Serial Settings Web: menu SERIAL CONFIGURATION, column Port N, Serial Settings. Telnet: SerialPorts, select Port N, Serial Settings The NetCom devices allow to operate in RS422/485 modes. This is configured by the Master DIP switches or by software, PortType (current) displays the current setting. Serial Settings Port Nr. 1 PortType (current) rs232 MaxBaudrate PortType rs232 Model Baudrate Manual 110 FlowType None DataBit 8 Parity None StopBit 1 RxFifoLength 2048 RxTriggerLevel [1248 ] TxFifoLength 2048 TxTriggerLevel [800 ] Figure 74: Serial Settings If the DIP switches are set for «Selected by Software», the mode of operation is chosen by the PortType parameter with following selections: April 2012 NetCom PRO User Manual 79

80 6 Configure the Operation Modes Figure 75: Operation Mode by Software rs232 rs422 rs485byart-4-wire rs485byart-2-wire-echo rs485byart-2-wire-noecho rs485byrts-4-wire rs485byrts-2-wire-echo rs485byrts-2-wire-noecho These are the same modes as available by configuration of DIP Switches. Using software configuration each port is functional independent from other ports. This is the only way to have different operation modes on a multi-port NetCom. The serial ports are based on enhanced UARTs, the Model and maximum speed are also displayed. The current UART Model may be virtually changed to a less advanced type. In some situations it may be desirable to deactivate the FIFO memory, or some other options. When the NetCom is used via the Virtual Com Driver mode, the following serial parameters are controlled by the application which opened the serial port. However certain installations use a different operation without Driver mode. Then the serial parameters must be defined via this configuration section. The Baudrate may be selected in a drop-down list of common values, or entered manually. If Manual is selected in the list, the value in the respective field is used to transmit data. NetCom checks if the configuration is possible, and warns otherwise. Note: The MaxBaudrate shown is kind of safe settings. It is achievable in RS 232-Mode with proper cabling. However, the NetCom may operate in RS 422 or RS 485 configuration. These are much less sensitive for noise. It is possible to configure a baudrate of four times the MaxBaudrate, usually bps. DataBit per character, Parity and StopBit are quite usual parameters. The FlowType is available as standard configuration. But there is also the option of Advanced Configuration. April 2012 NetCom PRO User Manual 80

81 6 Configure the Operation Modes FlowType Configuration Port Nr. 1 AutoCTS off AutoRTS off AutoDSR off AutoDTR off AutoTxXOnXOff off AutoRxXOnXOff off Figure 76: Advanced Flow Control This gives very specific control to the user. NetCom can generate Events on RTS, DTR or as XON/XOFF, when the serial receive buffer is filled/emptied. These will inform the connected device to stop or continue the transmission. The NetCom will also respect the state of CTS, DSR or XON/XOFF when sending data to the connected serial device. The RxTriggerLevel defines when NetCom sends the received data to the host. If the amount of data is this high, the data is sent. It does not matter if there is still data coming on the serial line. If less data is received, the NetCom waits some time for further data, before sending the buffer. When this parameter is reduced to 1 obviously all data is sent right when it has been received. The TxTriggerLevel operates similar for the transmission. If the defined amount is received from the network, the NetCom does not accept more data to transmit. These options reduce latency times, by increasing the network traffic. April 2012 NetCom PRO User Manual 81

82 6 Configure the Operation Modes Transfer Settings Web: menu SERIAL CONFIGURATION, column Port N, Transfer Settings. Telnet: SerialPorts, select Port N, Transfer Settings The Transfer Settings allow different operation modes. They are selected by the basic Mode setting. Depending on the current mode, only some of the many parameters are useful. The web configuration hides those parameters without function. SerialPorts Serial Settings Transfer Settings Transfer Settings Port Nr. 1 Mode Driver Mode Null Modem Tunnel TCP Raw Server TCP Raw Client TCP Advanced Settings UDP Mode IP Modem Print Server Point to Point Protocol Figure 77: Serial Port Mode Selection The following paragraphs explain these operation modes as well as their parameters and configuration in detail Driver Mode Only very few parameters have a function in Driver Mode. NetCom is operating as a Server in TCP mode, it accepts two connections per serial port. This mode is required when the driver software for Virtual Com Ports shall be used. April 2012 NetCom PRO User Manual 82

83 6 Configure the Operation Modes Mode Driver Mode TCP Port(Control) [2000 ] TCP Port(Data) [2001 ] KeepAliveMode On Connect KeepAliveInterval [0 ] Figure 78: Driver Mode parameters The first connection is used to transmit the serial data, this is the TCP Port(Data). And the other is used to transmit control information, TCP Port(Control). This control connection includes the configuration of the serial port, as well as signals for changed Modem Status lines. This mode is required when the serial port is operated via the Virtual Com Driver, it is the default. In Driver Mode the NetCom accepts only one client per serial port. An attempt to connect a second client is actively refused. This is required to avoid confused configurations and data on the serial port. The NetCom can monitor an open connection. This is controlled by the KeepAliveMode, which has three settings: Off, On Connect and Polling. Off: never send KeepAlive packets. On Connect: when a client is trying to connect to the server and there was a connection before, the server checks if the first connection still exists. If it does not exist anymore, the server accepts the new connection. This option is the default configuration. Polling: the server checks in KeepAliveInterval (seconds), if a connection still exists. If the network connection between client and NetCom seems to be unstable, the configuration of Polling may be desired. This way the NetCom may detect when the connection got lost. When the NetCom detects a lost connection, this is discarded, so the NetCom is available for other clients. Disabling the check is not recommended TCP Raw Server As Raw Server the NetCom operates very simple. It only waits for incoming data connections in Raw IP mode. In contrast to the Driver Mode no driver software needs to be installed on client computers, this mode operates directly on the TCP/IP stack in April 2012 NetCom PRO User Manual 83

84 6 Configure the Operation Modes the operating system. above (3.1). The parameters of the serial port are defined on the NetCom, as given Mode Raw Server TCP Port(Control) [2000 ] Max.Clients [1 ] Password [******] Figure 79: TCP Raw Server parameters Compared to the Driver Mode only the data connection is defined by the TCP Port(Data). The Max.Clients parameter allows for more than one connection to the NetCom at a time. If the number is raised, it is the responsibility of the customer to ensure correct operation. There is no special Keep Alive option, the global parameters from section apply. Firmware version 2.2 added the option of additional protection by Password. When a password is configured, the NetCom sends the question "Password: " to the client. The user (his application) must first send the password, followed by a <CR> character. The password is not echoed to allow usage with Telnet on a Monitor TCP Raw Client Also as Raw Client the NetCom requires very few parameters. The client computer operates via the TCP/IP stack as in , but now this computers waits for incoming connections opened by the NetCom. Using this mode several NetCom may connect to the same server software installation. The parameters of the serial port are defined on the NetCom, as given above (3.1). When the client computer is another NetCom in TCP Raw Server mode, this will virtually connect the devices attached to the serial port. April 2012 NetCom PRO User Manual 84

85 6 Configure the Operation Modes Mode Raw Client Destination [ :2001 ] Connect Triggered ShortHoldTime [0 ] Figure 80: TCP Raw Client parameters Under certain conditions the NetCom establishes a Raw TCP connection to a pre-defined Destination. Since version 2.0 of the NetCom Firmware the Destination can hold multiple hosts as targets for a connection. They are entered as a comma separated list of DNS names or IP Addresses. Each destination will have a TCP port number, separated by a colon. Instead of a single IP Address or DNS name, a range of IP Addresses is also valid. This range must be followed by the TCP port number, as in :2077. The parameter Connect defines if NetCom uses the connections as Permanent, Triggered or by DSR. With Permanent the NetCom attempts to open the connection as soon as it is available. In Triggered mode any activity on the serial ports establishes the connection, inactivity of longer than the ShortHoldTime cause NetCom to close the connection. With DSR the TCP-connections follow the state of the DSR signal at the NetCom serial port. When it becomes active they are established, until DSR becomes inactive. At that moment the connections are dropped Null Modem Tunnel This operation mode is intended to build a long virtual Null Modem Cable between the serial ports of two NetCom. This mode is symmetric, both NetCom operate as server and as client at the same time. The parameters of the serial port are defined on the NetCom, as given above (3.1). April 2012 NetCom PRO User Manual 85

86 6 Configure the Operation Modes Mode Null Modem Tunnel Server TCP Port(Control) [2000 ] TCP Port(Data) [2001 ] Client Destination [ ] TCP Port(Control) [2000 ] TCP Port(Data) [2001 ] Connect Triggered ShortHoldTime [0 ] KeepAliveMode On Connect KeepAliveInterval [0 ] Figure 81: Null Modem Tunnel This is a mixed mode, requiring parameters for server function and for the client part. The NetCom operates as a server while accepting connections in Driver Mode ( ). If there is no current connection, the NetCom may establish a connection as a client. This is also a special connection, using the Driver Mode protocol. NetCom will not only transmit serial data in both directions, it will also pass information about the current settings of the Modem Status lines. And it will itself set the Modem Control lines as required by the other host. The CTS is connected to the RTS of the partner, and DSR connects to DTR. Since this operation requires another NetCom to accept the connection, both NetCom together operate as a long Null-Modem cable. The data is sent via a tunnel through the network. The configuration as Server (top part) requires the same parameters as the Driver Mode, hence TCP Port(Control) and TCP Port(Data). Also the KeepAlive function operates the same. The configuration as Client (bottom) first requires a destination. Here it is given by name, but a direct IP Address may be more usual. On the destination there is also a TCP Port(Control) and TCP Port(Data) to accept the connect of the NetCom. April 2012 NetCom PRO User Manual 86

87 6 Configure the Operation Modes The Connect methods are the same as with the TCP Raw Client mode. So connections to the partners are permanent, last until there is no activity for a given time, or they are controlled by the DSR signal. Attention: You must not configure both NetCom with a Connect option configured as Permanent. This will result in each of them attempting to contact the other at the same time. Both NetCom will reject the connect, because they are already busy establishing a connect of their own. Instead create an asymmetric configuration: either use one of the NetCom in Driver Mode, or configure it with an empty Destination parameter. Or consider to have a connection on demand, i.e. use the Triggered option TCP Advanced Settings All of the above operation modes are special configurations for options. In some situations none of the pre-defined modes fit the customers needs. When this is the case, the TCP Advanced Settings offer the configuration of any Transfer parameter. Unusual combinations of Modes are possible with this, also standard modes with unusual parameters. April 2012 NetCom PRO User Manual 87

88 6 Configure the Operation Modes Transfer Settings Port Nr. 1 Mode TCP Advanced Settings Server On TCP Port(Control) [2000 ] TCP Port(Data) [2001 ] Max.Clients [1 ] Client Off Destination [ ] TCP Port(Control) [2000 ] TCP Port(Data) [2001 ] Connect Triggered ShortHoldTime [0 ] KeepAliveMode On Connect KeepAliveInterval [0 ] Figure 82: TCP Advanced Settings The NetCom usually acts as a network server. This means it accepts incoming connections. The most used Driver Mode is one example. The NetCom detects which mode to use. When the Data-Port is opened first, then the NetCom operates in TCP Raw Server mode, with respect to Max.Client. When the Control-Port is opened first, the NetCom expects a second connection on the Data port, to operate in Driver Mode for one client only. The NetCom can also operate as a network client as seen in TCP Raw Client mode. This is enabled by setting Client to On. As a client it requires the same parameter as for the specialized modes. When the TCP Port(Control) is defined (not zero), the NetCom will operate as a client for Driver Mode, as in Null Modem Tunnel. The destination is the target address or DNS name. April 2012 NetCom PRO User Manual 88

89 6 Configure the Operation Modes Otherwise the NetCom operates in TCP Raw Client mode when it establishes a connection. The syntax for multiple destinations applies then. The remaining parameters are explained in the client mode descriptions. The TCP Advanced Settings allow for flexible usage of the NetCom, when Server and Client modes are On at the same time. If no connection is active with the NetCom, it accepts incoming connections, i.e. it operates as server as long as the connections are held. Without a connection a Trigger event defined in Connect cause the NetCom to establish a connection to the defined target. So the NetCom is a client at that time UDP Data Transfer UDP is an Internet Protocol, which does not define a connection, it sends data in single packets instead of a stream. There is no extra return data to signal a successful transmission. As a side effect data may be sent and received faster than with TCP/IP. The UDP mode is available as a function since the version 1.4 of the NetCom firmware. Mode UDP Mode UDP Port(Local) [2002 ] Destination [ ] UDP Port(Dest) [2002 ] UDP MaxPacketSize [1458 ] UDP Timeout [0 ] UDP Trigger [ ] Figure 83: UDP Data Transfer This protocol requires a UDP Port(local) for listening to incoming data. Other stations on the network send their data to this port. The Destination host is configured by IP Address or name, plus the target UDP Port(Dest). Please compare with the parameters for TCP Raw Server and Client Modes. The parameters to configure the UDP Mode are similar to a mixture of these modes. A UDP Broadcast is sent, if the destination address is the broadcast Address, see section above. Since there is no connection, data can not be sent in a stream. UDP uses packages. There are several ways to define the content for a package. April 2012 NetCom PRO User Manual 89

90 6 Configure the Operation Modes UDP MaxPacketSize is a limit for the size of UDP packets. When the amount of data received on the serial port reaches this limit, the UDP Frame is assembled and sent to the destination. UDP Timeout defines when the NetCom sends the received data as a UDP Frame. If the reception of serial data is interrupted for this time (in milliseconds), the data sampled so far is sent to the destination. A value of zero causes all data to be sent immediately, use -1 to disable the function of timeout trigger. UDP Trigger defines a sequence of characters. As soon as this sequence is detected in the received data, all data up to the end of this Trigger is sent to the destination. In most situations such a Trigger includes control or other special characters. Enter them numeric: as \xhh where HH is the hexadecadic code of the character, or as \OOO where OOO is the octal code of the character. The backslash itself must be doubled as \\ IP-Modem The serial port of a NetCom may mimic (emulate) a serial modem. There is the separate section 7 defining this functionality. Here are the basic network parameters only. Mode IP Modem TCP Port(Data) [2001 ] Destination [ ] IP Modem Config [ ] Figure 84: IP-Modem A serial modem accepts connections from a phone line, while an IP Modem accepts connections from the network, in this case via TCP/IP. The TCP port for this is defined as the TCP Port(Data), similar to TCP Raw Server mode. This is the only parameter required to set here. All other values are normally defined by AT-commands via the serial port. However for short, Destination allows for up to four predefined targets, available with special Dial commands. The IP Modem Config is known as the Init String in standard modems. April 2012 NetCom PRO User Manual 90

91 6 Configure the Operation Modes Print Server Function The NetCom firmware version 2.2 introduces the function as a Print Server according to RFC1179, also called a»line printer daemon«. A print server is accessed through its IP Address via one specified TCP Port (see section ). Data is handled in distinct queues, each with a certain name. Each queue is handled by a certain serial port, and the data is sent to the serial printer attached to this port. Port Nr. 1 Mode Print Server QueueName [lpd1 ] InitString [ ] Figure 85: Print Server Configuration Each serial port configured for Print Server operation has its separate QueueName. The default value is»lpd«plus port number. The InitString is a special feature of NetCom. This string is sent to the serial printer at the beginning of the next queued print job. The definition is in section on page 115. April 2012 NetCom PRO User Manual 91

92 6 Configure the Operation Modes PPP Network Configuration The NetCom firmware version 2.4 offers the network access via PPP(13) over the serial ports of the NetCom. This function is not designed to allow routing of information from one station to another, passing the NetCom. It provides access to the NetCom and its internal functions via means of PPP network. The serial port of the NetCom may operate as a PPP Server, i.e. it will accept incoming calls (Dial- In). However as a Client it may also establish PPP connections by itself (Dial-Out). This section here just explains how to configure the NetCom for the operation. The technical information about the required parameters is given in section 10. April 2012 NetCom PRO User Manual 92

93 6 Configure the Operation Modes Port Nr. 1 Mode Point to Point Protocol Mode Client-Server Dynamic Addresses Enabled Idle Timeout [0 ] Modem Mode Modem Default Route Disabled Server Local IP Address [ ] Remote IP Address [ ] Client Configuration on the next Site Client Username [user13 ] Password [passwd13 ] Dial String [ATDT ] Modem Init-String [ ] Local IP Address [ ] Remote IP Address [ ] Netmask [ ] Figure 86: PPP Configuration April 2012 NetCom PRO User Manual 93

94 6 Configure the Operation Modes The serial port may operate in the combined PPP Mode of Client-Server, or the operation may be restricted to only one of those two. With Dynamic Addresses as Enabled the NetCom accepts the Assignment of an IP Address from a PPP Server. The NetCom operates as PPP Client to use this. When this option is Disabled, fixed addresses are predefined below. When no data has been sent for the Idle Timeout (in seconds), the PPP-Link will be closed. Use the value zero to disable the timeout. The serial port may operate via a real Modem (analogue, ISDN, GPRS,...), or via a Nullmodem cable. A Nullmodem cable only partially emulates the functions of a Modem. The Modem Mode parameter selects the different ways of operation. The PPP-interface may have the Default Route function on the PPP-Link as Enabled or Disabled. When the serial port is operating as a PPP Server, it will require a Local IP Address for its end of the PPP-Link. Likewise the Remote IP Address is assigned to the connected station, if this requests such. The client part of configuration is directly visible in the web browser interface. Via Telnet or serial port use the Left- and Right-keys to change between Server and Client parameters. When the serial port is operating as a PPP Client, there is of course a PPP Server to contact to. To get access to this Server the NetCom will use an account on the server. The accounts consists of a Username and a Password, which are configured in the NetCom. This account is used by this serial port only, other serial ports on the NetCom require separate account configuration. PPP operates via an operational serial connection. To open this connection a real Modem must dial to the target modem first. This will require a phone number for the target. Instead of only configuring the phone number, the NetCom accepts a complete Dial String. This string contains the phone number, but also may have certain commands to the Modem. Likewise a real Modem may require special configuration prior to operate for PPP. This initialization is provided by the Modem Init-String. When the PPP-Link is established, the NetCom may accept the assignment of an IP Address from the server. If this feature is Disabled, or the server does not provide the address, the NetCom uses the Local IP Address for its own end of the PPP-Link. The Remote IP Address is used together with the Netmask. They define a network route for IP data frames. The NetCom uses these parameters to decide whether a certain communication shall use the PPP-Link or a different network interface Save Web: menu SERIAL CONFIGURATION, at bottom. Again at the bottom of the web page below all the serial port options there is the button Save. This will store all configurations done for the current group of serial ports. Selecting a different group of ports or another configuration section from the menu may discard all changes done. April 2012 NetCom PRO User Manual 94

95 6 Configure the Operation Modes NetCom Tools Several tools for system status, checks and debugging are available in the Firmware. The available tools are: The Ping utility to check if a station is available. Statistic information for each serial port. The Netstat utility to monitor used TCP connections. The option to detect WLAN devices in the proximity (NetCom WLAN only) The option to update the firmware. Saving of Configuration to / Loading from a file (web browser only). Information logging by Syslog function and a DebugLog via TCP/IP. In your web browser click on the Icon of TOOLS, the browser opens the list of available tools. In Telnet the Tools menu provides a list of the tools. April 2012 NetCom PRO User Manual 95

96 6 Configure the Operation Modes Ping Web: menu Tools, section Ping. Telnet: Tools, option Ping. Enter the IP Address or the name of a station in the field. In the web browser click the Ping button, hit the <Enter>-key via Telnet. The network connection is checked by sending ICMP Echo Request data packages. PING from : 44 (72) bytes of data 52 bytes from : icmp_seq=0 ttl=255 time=1.560 msec 52 bytes from : icmp_seq=0 ttl=255 time=1.542 msec 52 bytes from : icmp_seq=0 ttl=255 time=1.542 msec back Figure 87: Ping and Response in Web Browser Tools Ping Statistic Netstat Wireless Logging Firmware IP-Address to ping to: [ ] PING from : 44 (72) bytes of data. 52 bytes from : icmp_seq=0 ttl=64 time=< 10 ms 52 bytes from : icmp_seq=1 ttl=64 time=< 10 ms 52 bytes from : icmp_seq=2 ttl=64 time=< 10 ms 52 bytes from : icmp_seq=3 ttl=64 time=< 10 ms Figure 88: Ping and Response in Telnet If the target responds, the network between the NetCom and the target is operational. The time required for an echo depends on the speed of the network. In a typical Ethernet this is only very few Milliseconds, while it can be several seconds throughout the Internet. Via Telnet use the <Esc>-key to stop the Ping function Statistics Web: menu Tools, section Statistics. Telnet: Tools, option Statistics. April 2012 NetCom PRO User Manual 96

97 6 Configure the Operation Modes The Statistics are presented on a by-port base. So you first select the serial port, and then you get the information about modem status and control. Also the amount of data transferred is shown. Tools Ping Statistic Netstat Wireless Logging Firmware Tools Port 1 Port 2 Port 3 Port Figure 89: Statistics Port Selection Line Status DTR off (0) DSR off (0) RTS off (0) CTS off (0) DCD off (0) RI off (0) Common Serial Tx 0 Serial Rx 0 Figure 90: Port Statistics The statistics window 8 reports the state of the modem status and control signals. Further the NetCom counts the number of status changes on the modem control- and status-signals, since the NetCom has been started. The number of characters sent and received is shown at the bottom Netstat Web: menu Tools, section Netstat. Telnet: Tools, option Netstat. Netstat is a common tool to display the actual status of network connections. It may be used to monitor the actual status of the NetCom. This is a standard tool for network debugging. 8 The web browser opens a separate window for each port selected April 2012 NetCom PRO User Manual 97

98 6 Configure the Operation Modes Figure 91: Start Netstat Tools Ping Statistic Netstat Wireless Logging Firmware Update Proto Local Address Foreign Address State tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :1280 TIMEWAIT tcp : :1281 ESTABLISHED udp :161 udp :19970 udp : /1 Proto Local Address Foreign Address State tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :0 LISTEN tcp : :3665 ESTABLISHED udp :161 udp :33320 udp :10397 Figure 92: Netstat Sample Output A Foreign Address of is listed when NetCom is waiting for an incoming connection (LISTEN mode). If the value is not , the connection is either active (ESTABLISHED) or already closed (TIMEWAIT). In the web browser you may Update the Netstat output. Via Telnet the output may not fit on the screen, then the display will start with 1/2" in the first line. Or even more for a long list. You may change to a different page by using the Page Up/Down April 2012 NetCom PRO User Manual 98

99 6 Configure the Operation Modes keys in your Telnet. The display is refreshed in an interval of some seconds. Use <Esc>-key to return to the menu. April 2012 NetCom PRO User Manual 99

100 6 Configure the Operation Modes Wireless Web: menu Tools, section Wireless. Telnet: Tools, option Wireless. When Wireless communications is intended, it is useful to see a list of possible partner stations on the WLAN. This function is available in many driver packages for Windows, and also in the NetCom WLAN Serial Device Servers. This function is often referred to as»range Scan«. Figure 93: WLAN Scan Tools Ping Statistic Netstat Wireless Logging Firmware On the NetCom WLAN it will open a separate browser window with the results. An example of this is shown below. Telnet displays the results. Wireless-Devices in Range Update Act MAC SSID Channel Mode Enc X 86:73:F6:22:E1:BA NetCom_ Ad-Hoc X A6:E8:9E:BE:7D:86 NetCom_ Ad-Hoc X 00:0F:B5:66:CF:56 NETGEAR 11 Managed X Current Rate: 11Mb/s Act MAC SSID Ch Mode Enc X 86:73:F6:22:E1:BA NetCom_ Ad-Hoc A6:E8:9E:BE:7D:86 NetCom_ Ad-Hoc X 00:0F:B5:66:CF:56 NETGEAR 11 Managed X Current Rate: 11Mb/s Figure 94: WLAN Scan Output This example lists two other NetCom WLAN configured for Ad-Hoc communication on channel 7. Both do not use encryption. There is also an Access Point (listed as Managed), of course in Infrastructure-mode. To connect to this AP the NetCom WLAN must use encryption. Since the NetCom WLAN itself is in Ad-Hoc mode, the communication is limited to the b, which results in 11Mb/s as raw transmission speed. Further the encryption is limited to the WEP methods. In Telnet the display is updated automatically when some information changes. Most noticeably this will be the Act-ivity sign. April 2012 NetCom PRO User Manual 100

101 6 Configure the Operation Modes Firmware Web: menu Tools, section FirmwareUpdate. Telnet: Tools, option Firmware. To upload a new version of the firmware, put the name of the file in the field. Your web browser will allow to search for the file. Click on the Update button, and your browser will upload the file to the NetCom. Tools Ping Statistic Netstat Wireless Logging Firmware Firmware Update Update Port [2400 ] [ Start Update ] Figure 95: Firmware Upload Via Telnet the option to upgrade the Firmware of NetCom is different. The upload of the data is either done via the current channel (i.e. the serial or Telnet connection). Or independently via a separate TCP/IP connection. The Update Port parameter defines this second connection, the NetCom waits for a TCP connection on this port. The Firmware is sent coded in base64 (a special text format), via very simple programs like a second Telnet session, or similar tools. Terminal software by serial configuration may just use the Send Textfile function. While uploading the file it is checked by NetCom. If it is a valid content, it is stored in the Flash Memory. When the upload is finished, NetCom will Reboot Save and Load Configuration Web: menu Tools, section Configuration File. Via web browser it is possible to save the actual configuration to a text file. Of course it is also possible to load the saved configuration into a NetCom. April 2012 NetCom PRO User Manual 101

102 6 Configure the Operation Modes Figure 96: Save and Load Configuration in Web Browser This may be very useful when configuring several NetCom of the same type. Configure one device, and save the file. Change the configuration file for the necessary parameters, and upload the modified version to the next model Logging and Debug Web: menu Tools, section Syslogging. Telnet: Tools, option Logging. The NetCom has two options of Logging. There is the standard Syslog, and a second option of logging via Telnet. Tools Ping Statistic Netstat Wireless Logging Firmware Logging Syslog Off Destination [ ] Facility [1 ] Debuglog Off Debug Port [0 ] Figure 97: Syslog & Debuglog Parameters The Syslog function may of course be Off or On. In the On-state the NetCom sends all the log information to a computer defined by Destination. A special software often called Syslog Daemon April 2012 NetCom PRO User Manual 102

103 6 Configure the Operation Modes has to receive these data. The Option of Facility is a criteria for the Daemon how this will organize the data received from the NetCom. In contrast for Debuglog the NetCom behaves as the server. When this option is On the NetCom waits for incoming TCP connections to the configured Debug Port. The NetCom sends all logging information via this connection. For manual use a software like Telnet is suitable, especially if it has the option to save all received data Save Web: menu Tools, at bottom. As usual at the bottom of the web page below all the options there is the button Save. This will store the configurations done for Logging ( ) Reboot Web: menu REBOOT. In your web browser, click the Icon of REBOOT to restart the NetCom firmware. Attention: This option will discard all configuration changes, unless they have explicitly been saved. Naturally it will also disconnect all other clients using serial ports or the Telnet configuration menu Save&Exit Menu This section of configuration is only available via the terminal interface, i.e. via Telnet or serial port. Modifications in the configuration of the NetCom are not active, until they are explicitly saved to the Flash Memory of NetCom. This menu also allows to discard all changes, and even to restart the firmware Save Parameter Telnet: Save&Exit, option Save Parameter. When some changes are done, these modified settings should be saved. A confirmation is requested before doing this. Save&Exit Save Parameter Exit Reboot Do you want to save the changes Yes No Figure 98: Menu Save modified Parameters in Telnet The Telnet interface is still active when this operation is finished. April 2012 NetCom PRO User Manual 103

104 6 Configure the Operation Modes Exit Telnet: Save&Exit, option Exit. You will not be surprised, when you leave the menu by selecting this option. If you made any changes of parameters, you must confirm to save these. Save&Exit Save Parameter Exit Reboot Do you want to save the changes Yes No Figure 99: Menu Exit from Configuration in Telnet The NetCom terminates the Telnet interface when this operation is finished, even when the modifications are not saved to Flash Memory Reboot Telnet: Save&Exit, option Reboot. Users may restart the firmware of the NetCom. Modified configurations are activated by the restart process. Such a restart is necessary for some changes like IP configuration, others do not require a restart. Save&Exit Save Parameter Exit Reboot Do you want to save the changes Yes No Figure 100: Exit and Reboot in Telnet Also here, if parameters are changed during the session, confirmation for saving them is requested. Of course the Telnet configuration is closed, because all TCP connections are terminated by the reboot process. 6.3 Erase Configuration of NetCom Sometimes it is required to clear any configuration done, and go back to the Factory Settings. Users might think this is possible with the Reset button. It is not done this way. The Reset button is just a way to restart the NetCom without removing the power. To make a clean configuration the DIP switches must be configured to the pattern of "Factory settings". Refer to Section 3.1 or to the table on top of the NetCom case. When this pattern is chosen, the NetCom has to be restarted, by power off or by using the Reset button. This is for security. When changing a DIP configuration, the Factory settings might appear by accident. So the NetCom requires to be restarted with this DIP pattern active to avoid accidental damage of the configuration. While restarting, the NetCom erases the current configuration, and replaces April 2012 NetCom PRO User Manual 104

105 6 Configure the Operation Modes the parameter with the default values. When this is finished, the Power LED blinks once. Do not power off or reset the NetCom before this blink is seen. The Ethernet cable should not be connected, because the NetCom uses DHCP in factory configuration. Without an Ethernet cable it does not attempt to find a DHCP server, which makes a faster reboot process. April 2012 NetCom PRO User Manual 105

106 7 IP Modem Function 7 IP Modem Function The Firmware offers the function of IP Modem. Used in this mode, the serial port of the NetCom emulates a standard serial modem. Basically this means the NetCom will a) answer to AT-commands on the serial port b) establish a connection to a destination c) inform the connected serial device of the connection d) accept a TCP connection, and inform the serial device of that event For connections the NetCom will use a TCP connection. This differs from a normal telephone line, so there will be some modifications in the behavior. The target is an IP Address, not a phone number. Also for hardware reasons the automatic baudrate detection used in today serial Modems is not available. However this is not a problem at all, the IP Modem can be installed in Windows as a Standard 33600bps Modem. There is an INF-file for ease of installation. 7.1 Some possible Scenarios 1. The customer has a remote management installation, operating via telephone line. These lines may be in-house or through public phone systems to other destinations. The customer wants to reduce costs for these lines, management and possibly hardware, using the Intraor Internet. 2. The customer wants to contact several stations from a central server. Because of frequent target changes he does not want to define the target by a Virtual Com Port. 3. Remotely distributed devices contact a central system by Modem. This is the reverse of option A computer without Network access shall have at least limited control on the connections established by a NetCom. 5. Old fashioned BBS installations become accessible via Internet. The typical multi-modem box is replaced by a NetCom Server with multiple ports configured for IP Modem operation. 7.2 Serial Signals and Cables A real modem provides the same signals as the serial port of a PC. However, where a signal is an output on the PC, it is an input to the modem, and vice versa. So in the NetCom the emulation of a modem must be incomplete. By exchanging RxD and TxD the data connection is fine, the same happens for handshaking signals RTS and CTS. The DTR of the PC is connected to DSR of NetCom, this is simple. The RI may be ignored, some connectors for serial ports also do that. However a real modem provides DSR and DCD to the PC. There is only the DTR left on NetCom to serve these signals. In most configurations the NetCom-DTR serves as the DCD to the computer. April 2012 NetCom PRO User Manual 106

107 7 IP Modem Function The cable must provide a DSR to the PC then, e.g. by shortcut to the PC-DTR. In some configurations the NetCom-DTR must serve as the DSR. This is configurable by a command. The recommended cable connects as shown in this table. Please note, this installation does not use the simply crossed signals. Especially the DSR of the PC is internally connected to the DTR of the PC. DB9m PC IP-Modem DB9m DB9f 3 TxD RxD RxD TxD RTS CTS CTS RTS DSR PC-DTR (internal loop-back) 4 DTR DSR DCD DTR GND GND 5 5 Table 17: IP Modem cable The limitation of signals is a restriction in function, compared to real world serial modems. Since most installations do not require the full availability of all signals, the required subset can be selected. 7.3 Operation Modes by IP Modem The function of IP-Modem may be configured port by port. On a NetCom with a single port there is no much of a difference. However a NetCom with more serial ports operates each port independently. In the following sections of this manual the phrase "serial port of a NetCom, configured to operate as IP Modem" is replaced by "IP Modem" for brevity. Two basic operation modes are available. The first and default mode is Modem-to-Modem. This requires a serial port of a NetCom configured as IP Modem on both ends of the connection. When one IP Modem dials the other, the connection is established on the TCP level. Directly afterward both IP Modems negotiate to ensure they are a real NetCom IP Modem and are free for connection. If successful both issue a "CONNECT... " response to the serial connected devices. This is convenient for the customer to understand. The CONNECT may report some parameters, e.g. the minimum serial speed used by both Modems. These extra parameters are not implemented so far. The other mode is named as Modem-to-Host. The destination is any software, which opens a TCP port for Listen mode. It may be a second NetCom configured for TCP Raw Server Mode. It may also be the customers application, running on a certain computer. This mode offers less features. 7.4 Hayes Commands The IP Modem operates with a command set similar to those in real Modems. All of the commands start with the character sequence AT. April 2012 NetCom PRO User Manual 107

108 7 IP Modem Function AT command set The following table lists many standard commands (in alphabetical order). The AT is omitted for brevity. The discussion of the functions is below the tables in section 7.5 below Standard AT-Commands These commands are based on the old Hayes Modem. AT Hayes-Standard IP Modem Function A Answer Call Accept a connection Bn ITU-T modulation Define some modem operation modes Dnnn Dial connection, basically phone number as nnn Connect to the target system by IP Address and TCP-Port. E.g. ATD10,0,8,42,2023 will "dial" to port 2023 on IP Address E Echo on/off Enable/Disable local echo of command H0 Hang up Terminate the TCP connection I Device Information I0 through I9 report information L Speaker Volume Ignored, always answered with OK M Speaker On/Off Ignored, always answered with OK N Auto serial speed N0 no Auto, N1 reports error O Return to data mode Q Result Codes Enable or disable result codes/strings S=nn/S? S-Register Set/request configuration registers V0/1 Responses Numeric/text responses to commands X Busy/Dial detect Ignored, always answered with OK Z Reset to User profile Standard Table 18: IP Modem Standard AT Commands Extended AT-Commands These commands are used in modern modems, and have slightly different syntax depending on the model. AT Standard-Extensions IP Modem Function &C DCD control When to turn on DCD (by IP Modems DTR) &D DTR meaning Hang Up, Command Mode or Reset &F Load factory Default &K Flow Control &S DSR control When to turn on DSR (by IP Modems DTR) &V View Profiles &W Store Profile &W0/&W1 is "Standard". ATZ1 loads profile 1 &Zn=dd Save for short dial Define possible targets by DNS name or IP Address %C1 V.42bis enable Ignored \Q Flow control See &K Table 19: IP Modem Extended AT-Commands April 2012 NetCom PRO User Manual 108

109 7 IP Modem Function Non-AT commands All these commands apply in Command Mode. If a Dial command or an ATA succeeds with a CONNECT, the IP Modem is in data mode. Every data received on the serial port is sent to the other station/ip Modem. And there is a special character sequence in Data Mode, which changes back to Command Mode. This sequence is +++ by default, with an interval of 1 second before and after this command; the three characters must appear in one second S-Registers for Configuration Traditional there is a set of registers to control certain operations. These registers are controlled via the AT S-command mentioned above. This is a list of those supported by IP Modem. Reg. Function Range/units Default S0 Auto-Answer Ring (no Auto-Answer) S1 Ring Counter (read only) S2 Escape Code (ASCII) 43 (= "+" for "+++") S3 Carriage Return S4 Line feed S5 Backspace 0-32, S8 Comma pause (seconds) Accept but ignore S9 Carrier detect response time (0.1 sec) 6 S12 Escape Guard time (0.02 sec) 50 (= 1 second) S25 DTR Ready Delay (0.01 sec) 5 (= 50 msecs) S26 RTS to CTS Delay (0.01 sec) 1 (= 10 msecs) S30 Disconnect Timer 0-90 (seconds) 0 (read only, AT\Tnn) Table 20: IP Modem S-Registers for Configuration S0 is frequently used to configure a modem to auto answer incoming calls. S1 may be checked by software if S0 is Zero, i.e. no Auto-Answer. S2 may be set to a different character, if the +++ may happen in typical data. Otherwise the software must insert a pause in the transmission Sample Commands used by Windows The NetCom IP Modem is intended for manual installation as kind of a "Standard Modem" in Windows. The reference is the MDMGEN.INF file. The commands used in that file are: "AT&F", "ATA", "ATH", "AT &F E0 V1 &C1 &D2 S95=47 S0=0<cr>", "ATS0=0<cr>", "ATX4", "ATS7=<#>", "AT%C", "AT\N", "AT&K", "ATS30=<#>", "ATB", "ATDP", "ATDT", "ATL", "ATM" 7.5 Description of AT Commands The commands are listed more or less in a functional grouping. Configuration commands are listed also with their default settings in brackets. April 2012 NetCom PRO User Manual 109

110 7 IP Modem Function AT D (dial) This is the general Dial command. The target is defined as IP Address plus TCP-port number. The dots in the address are replaced by a comma, and the TCP port is also separated by a comma. On normal modems a comma generates a pause in the dialing sequence. This is commonly required, so all software will support it; even multiple comma. The modifiers T for Touch Tone and P for Pulse dialing have no direct equivalent on the TCP connection. They are used to change between Modem and Host mode, if the ATB command enables this (ATB2 or ATB3). Otherwise the IP Modem will ignore them. Basically dialing is done to a given IP Address plus a TCP port number. The IP Address is given in decimal Octet format, where comma replaces the dot as the separator. This is followed by another comma, separating the TCP Port from the IP Address. If the port is omitted, the target port is the same as the local TCP Data Port as defined in the configuration of IP Modem (see above). There are situations where the target is known by a DNS name. This name can not be used in a dial string, mostly because very few software will support it. So there is the option of dialing to a pre-defined entry by shortcut. This is given by an S followed by one or two digits. The shortcuts S90 to S99 are reserved; so far only S1 to S4 are implemented. Shortcuts are defined and saved by AT&Znn=<FDN:Port>. All other non-numeric characters are understood as modifiers. The IP Modem will simply ignore them. This especially applies to space characters. Typically dial strings are: ATDT192,168,254,254,2003<cr> AT&Z12=demokit.vscom.com.tw:23<cr> ATDPS12<cr> Dial another IP Modem as a Modem-to-Modem Define a shortcut for configuration port Dial the other IP Modem as Modem-to-Host Table 21: IP Modem Sample Dials AT O (online / data mode) If a connection is established, the IP Modem can still be in command mode. The ATO activates the transparent data mode AT A (answer call) Have the IP Modem answer an incoming call, and establish a TCP connection. This command is required if Auto-Answer is disabled. Observe the operation mode defined by ATB AT B (modulation) [ATB1] This command is used to define the modulation to use on the phone line. Since the only "modulation" available is IP, there is no choice. The command is used to change between Modem-to-Modem and Modem-to-Host mode. April 2012 NetCom PRO User Manual 110

111 7 IP Modem Function ATB0 ATB1 ATB2 ATB3 Modem-to-Host mode Modem-to-Modem mode, which is the default Modem-to-Modem when Touch Tone dialing, Modem-to-Host when Pulse dialing. Answer in Modem-to-Modem. Modem-to-Modem when Touch Tone dialing, Modem-to-Host when Pulse dialing. Answer in Modem-to-Host. Table 22: IP Modem virtual Modulation AT E (echo) [ATE1] Disable and enable the echo of the commands received. ATE0 to disable and ATE1 to enable the echo AT Q (quiet) [ATQ0] Configures the IP Modem to remain quiet. The Modem will not send any response messages to the serial port AT V (verbose) [ATV1] Responses as numeric values (ATV0) or as text strings (ATV1). OK 0 CONNECT 1 RING 2 NO CARRIER 3 ERROR 4 CONNECT NO DIALTONE 6 BUSY 7 NO ANSWER 8 Table 23: IP Modem Responses AT H (hangup) [ATH0] Command to disconnect. Also used as ATH0. The related version ATH1 to just go off-hook is not supported, and reports an ERROR AT I(n) (information) [ATI0] Report technical information about the IP Modem. It is frequently used to identify the device. The answer is always sent as <cr><lf><#response#><cr><lf><cr><lf>ok<cr><lf> Here are the defined #response#-strings. April 2012 NetCom PRO User Manual 111

112 7 IP Modem Function ATI or kbps maximum ATI0 ATI Mbps Ethernet ATI2 ATI3 Version 1.0 / <compile-date> Version of Modem-Firmware ATI4 Current Profile ATI5 ATI6 NetCom 230k IP-Modem Device Identification ATI7 ATI8 ATI9 (<Name>\Serial#\IP-#:port\Com-X\NetCom) Display serial port used ATI10 ATI11 <very extended information> Table 24: IP Modem Information Responses AT S (setup) Set and read the S-registers for configuration. ATSrr? is a request to read the current value of S-register number rr, ATSrr=nnn stores the value nnn in the register rr. Unknown registers report ERROR. See section above for possible registers and parameters AT L (loudness) and AT M (speaker) These commands are answered with OK, but completely ignored. speaker. There is no function like AT N (auto baud) [ATN0] Automatic detection of serial speed. For hardware reasons this detection is not implemented. The command ATN0 to disable automatic detection is accepted and answered with OK. The ATN1 to enable automatic detection is not available, and answered with the ERROR response AT Z (reset) Reset the configuration to a stored profile. IP Modem only supports profile 0 for simplicity. Same as ATZ0 or as AT&F or AT&F0. April 2012 NetCom PRO User Manual 112

113 7 IP Modem Function AT &F (factory settings) [AT&F0] This command has historically been designed as "Reset to Factory settings", while ATZ simply meant reset. At time of invention users could change the default behavior of their Modem, so ATZ activated the stored profile. Nowadays the ATZ is ignored by many software. Instead AT&F is used, followed by complex initialization strings. User may save profiles, which are selected by AT&F0 or AT&F1. There is no longer a documented or commonplace way to revert to Factory Defaults. The IP Modem has such an option (clear the InitString via Telnet/web), but this is not usable to reset the configuration when the device is used as a Modem. So IP Modem will support only user profile 0, and it uses AT&F9 to really reset the user profile to the Factory defaults AT &C (DCD configuration) [AT&C1] Configure the DCD signal to the PC. As IP Modem this signal may be generated by the DTR output. A standard modem can have DCD always on, and it can have the DCD follow the external carrier signal. When set to always on by AT&C0 the DCD may have a separate source. The DTR is free to serve as a DSR to the PC. The operation of DSR is defined by AT&S, so these commands are related. AT&C1 is the default, the DTR operates as DCD to the PC (this will require a cable connecting NetCom-DTR to the DCD of the PC). This command has priority over AT&S AT &S (DSR configuration) [AT&S0] Configure the DSR signal to the PC. As IP Modem this signal may be generated by the DTR output. A standard modem can have DSR always on, as long as the Modem has power. Or it can have the DSR signaling whether the IP Modem is in command or in data mode. When set to always on by AT&S0 (this is the default) the DSR may have a separate source. The DTR is free to serve as a DCD to the PC. The operation of DCD is defined by AT&C, so these commands are related. An AT&S1 has DSR follow the data mode. The AT&C has priority over this command. AT&S1 can only be effective, if AT&C0 is set AT &D (DTR configuration) [AT&D2] Understand the DTR signal of the PC. The input on the IP Modem is the DSR, which requires a proper serial cable. Usually this signal is either ignored, or serves to disconnect from the phone line. There are four options: AT&D0 Ignore DTR from PC AT&D1 Toggle DTR to enter command mode AT&D2 Toggle DTR to disconnect and enter command mode default AT&D3 Toggle DTR to reset the IP Modem perform ATZ Table 25: IP Modem DTR Configuration April 2012 NetCom PRO User Manual 113

114 7 IP Modem Function AT &K (handshake) [AT&K3] or as alternative command AT \Q [AT\Q3] Configure serial Flow Control. AT&K0 and AT\Q0 disable all Flow Control. The default is AT&K3 and AT\Q3 to use RTS/CTS Hardware Flow Control between PC and IP Modem. AT&K4 and AT\Q1 configure for XON/XOFF Software Flow Control between PC and IP Modem. Other Options are not supported AT &V (view profile) Show Profiles. This will display the current profile, the stored user profile, the short dial strings and the factory profile. Parameters are accepted but ignored. AT&V is AT&V0 and is AT&V AT &W (save profile) Save the current configuration as user profile. AT&W is the same as AT&W0, all other parameters report an ERROR AT &Z (save destination) This command will save a destination in Internet syntax. It is given by <host>:<port>. The <host> is either an IP Address in dotted octet notation, or an FQN in correct syntax. The <port> is a string representing a decimal number. If :<port> is omitted, the target port is the local TCP Data Port as defined in the configuration of IP Modem (see above). April 2012 NetCom PRO User Manual 114

115 8 Print Server Operation 8 Print Server Operation Sometimes the Serial Device Servers are used together with serial printers. These printers are available via a network to several stations for printing. So far there have been two operation modes to achieve this. First the serial port can operate as a TCP Raw Server, and the station just sends the data to print via a TCP connection. As second option a computer running Windows could install the driver for virtual serial ports. The printer is then controlled via this Com port. In both these solutions the buffering of data occurred on the client station. Beginning with Firmware version 2.2 the NetCom Devices offer a true Print Server mode, using the Line Printer Daemon protocol as of RFC1197. Here a print server (lpd) is a station with one IP Address and a single defined port to accept commands and data for printing. Several printers may be attached to the print server. Each printer has a separate data queue for management of print jobs. The data of the jobs is saved in this queue, instead of the client as before. 8.1 Printer Queue The basic function of an lpd is to accept the data for printing, store it in a spooler queue, and send it to the printer when this is ready for printing. This is done for several queues in parallel. Each printer is identified by the name of the queue, where it is attached to. The NetCom Device Servers allow to configure a custom name for each queue, while the default name is»lpd«plus the number of the serial port (lpd1, lpd2,... ). This name is set in the properties of the serial port. When the lpd is running on a separate computer, the hard disk is used to save the data of the queues. The NetCom Servers neither have a mass storage device, nor huge amounts of memory. Each queue accepts at least one job with a size of up to 250 KB print data. If the job has more data, memory is either assigned dynamically to save the job, or the data is spooled through a ring buffer. Data is printed while the client still sends data. The amount of available dynamic memory depends on the number of ports in a NetCom Device Server, and the operations active on these ports. 8.2 Printer Reset Before a new job is sent to the printer, this printer should be in a well known state. On a parallel printer port this is easy to achieve. There is a defined signal to send a»reset«command to the printer. Such a definition is not available for serial printers. Instead there is a reset command, which users may send via the serial line. Typically this command is specific to the manufacturer or even to the printer model. So the NetCom allows to specify this command by entering an InitString for each queue Init String Definition The Initialization of the printer typically involves ASCII control codes, ordinary ASCII characters and some binary data. On some models it may also be necessary to provide a certain state of the modem control signals RTS and DTR, applied with special timing. The InitString in the NetCom Device Serves offer all these options. April 2012 NetCom PRO User Manual 115

116 8 Print Server Operation ASCII Text Ordinary ASCII characters are entered as they are on the keyboard. The single exception is the Less Than character <, which is used for other special functions ASCII Control Codes ASCII control codes are entered by their standard name, enclosed in Angle Brackets, i.e. in < and > (Greater Than). Some examples of this are <ESC>, <CR> or <TAB> Numeric Codes Especially binary data must be sent by means of its numeric value. Since the < ASCII character has a special function, the only way to use this is the numeric method. This also applies to printable characters of some Extended ASCII character sets. The NetCom accept the decimal value, also enclosed in angle brackets. Up to three decimal digits define the character to send to the printer. The < is used as <60>, while the <ESC> may also sent as <027>. The > may be used directly, however for clarity <62> should be preferred Modem Control Signals Via the InitString control of RTS and DTR is available. This manual does not make statements about voltage levels on the signals, these are just set to an active or inactive state. <RTS+> and <RTS-> activate and deactivate the RTS signal, while <DTR+> and <DTR-> do the same for DTR Timing Options Especially when using Modem Control signals it will be required to hold them in a given state for a defined amount of time. This may be done by applying a»pause«- command in the InitString. The delay is given as numeric value in milliseconds (msec), preceded by a P. So <P50> causes the NetCom to wait 50 msec before proceeding with the next command or start printing. Up to three digits are possible. If more than 999 msec are required, the Pausecommand must be repeated. Please note: The delay is not executed as an exact time. NetCom guarantees to wait at least the required amount of time. The smallest delay possible is 10 msec, due to internal handling of date and time Reset Example For example here is a hypothetical serial printer. The serial port operates at 1200 bps, 7 bit and even parity and 1 stop bit. For Reset the printer requires the command "<ESC>@0" sent with DTR and RTS off. When the data is transmitted, DTR must be on, and 50 msec later RTS must also be on. Each character sent is 10 bits long, including the start bit. At 1200 bps each character needs 8.3 msec for transmission. So the transmission lasts for 25 msec. To be sure the control signals are inactive, an extra delay is applied after change of signals. The resulting string would be <RTS- ><DTR-><P10><ESC>@0<P35><DTR+><P50><RTS+> The delay of 35 msec after the command string "<ESC>@0" shall ensure, all data is completely transmitted to the printer. April 2012 NetCom PRO User Manual 116

117 8 Print Server Operation 8.3 Operation in Windows The Printer Server mode may be used to support serial printers in Windows Operating System. This is a short instruction how to install and use it. Experience on installing printers in Windows is required for this instruction. First the installation of a new printer is given, the modification of an existing printer setup is described later Add a New Printer From»Control Panel«open the»printers and Faxes«windows. Select the»add a printer«option. The usual»add Printer«Wizard appears. Click the "Next" button to select the port, where the printer is attached to. Figure 101: Add a printer Figure 102: Select Printer Port Select the option of»local Printer... «, but de-select the automatic detection of the printer type as shown below. Click the "Next" button to continue Create new printer port You need to create a new port for the printer, the required type is a»standard TCP/IP Port«. April 2012 NetCom PRO User Manual 117

118 8 Print Server Operation Figure 103: Create Printer Port In the»add Standard TCP/IP Port«Wizard just click the "Next" button, and have the NetCom Serial Device Server properly configured for LPD-operation Name the new Printer Port Then the properties of the new printer port must be entered. Figure 104: Name-Properties of Print Server Port You need the network address of the NetCom, this may be the IP Address or a DNS name for the device. The port name is only for internal identification in Windows. It will be listed in the possible ports to connect printers to. The name is similar to»lpt1:«or»com3:«, but it does not denote any real hardware in your computer. You are free to enter any name not used so far. The name is not related to the LPD Queue name on the NetCom. Again click the "Next" button. April 2012 NetCom PRO User Manual 118

119 8 Print Server Operation Configure the Printer Port As the last step in creating the printer port for your printer you need to enter some additional information. As the»device Type«select "Custom", and open the "Settings... ". Figure 105: Mode-Properties of Print Server Port Under»Port Settings«select the "LPR" protocol instead of the "Raw" method. The Port Number becomes unavailable, because the standard TCP Port 515 is used in this configuration. Enter the Queue name you configured in the NetCom. Each serial port on a NetCom has a separate Queue name to identify it. So it may be a good idea to name the queue after the printer attached to the serial port. Be sure to enable the "Byte Counting", because this is required by the Print Server function in the NetCom. Close these options with the "OK" button Install Printer Driver Now the printer port is installed, and the Printer installation Wizard continues. Select the printer from the list, or install a new type using an installation disk the usual way Modify an Existing Printer In several situations it is necessary to modify the configuration of a printer, which is already installed in Windows. For example, the mode of use shall be changed to Printer Server Mode, the printer is moved from a local serial port to a NetCom Serial Device Server, or the installation program of the printer only accepts local serial ports to attach the printer to. In such situations it is required to create a new lpd port, and modify the configuration of the printer Open the properties Again open»printers and Faxes«in the Control Panel. April 2012 NetCom PRO User Manual 119

120 8 Print Server Operation Figure 106: Select Port for Printer Select the installed printer, and open the properties. In the properties select the tab for»ports« Add the Print Server Port The button for "Add Port... " opens a dialog with the possible printer port types. Figure 107: Add Printer Port Select "Standard TCP/IP Port" and click on "New Port... ". This will open the Add TCP Port wizard as of section above. Proceed as described there. April 2012 NetCom PRO User Manual 120

121 9 OpenVPN Encryption 9 OpenVPN Encryption The NetCom PRO Serial Device Servers offer a special method of encrypted communication. Instead of modifying driver and application programs to support encryption (e.g. by using SSL), the NetCom PRO Servers provide a virtual direct network connection between the computer and the NetCom PRO. The function is similar to a cross-over Ethernet cable between the computer and the NetCom PRO. Such a technique is referred to as a "Virtual Private Network" or VPN for short. Encryption on this communication layer is totally different from WLAN Encryption like WEP or WPA, and it is independent of this option. Applications installed on the computer just see an added network connection, if they really care about network configuration. They do not need to, the system sends and receives all data for and from the NetCom PRO on this new link. Since this link is encrypted, no application cares about it. Even a simple Telnet session becomes secure this way. To establish the encrypted VPN link the NetCom PRO Servers use an Open Source product named OpenVPN ( OpenVPN is licensed under GPL, hence there is no added costs for using it. Currently OpenVPN is available for a wide range of systems, including Linux, Windows 2000 and above, as well as Mac OS X. OpenVPN is a product full of features. In conjunction with the NetCom PRO Servers only a limited part is used. The connection is established via a TCP connection, the IP Addresses are assigned static. Further NetCom PRO Servers use the conventional encryption with static-keys based on strong AES cipher (pre-shared keys). This section in the Manual will give information for the limited installation, and the use together with NetCom PRO Servers. 9.1 OpenVPN Installation As the first step for encrypted communication the system needs the client software for OpenVPN. This is a quite usual Application Wizard. You have to Accept a License Agreement, which is based on the GPL. Figure 108: OpenVPN Installation Wizard In the next step you have the option to select required components. All components are pre-selected. You may safely uncheck the»openvpn Source Code«. Figure 109: OpenVPN Installable Components April 2012 NetCom PRO User Manual 121

122 9 OpenVPN Encryption Proceed the installation by choosing a path for the program and related files.»openvpn«in your program files folder is suggested as with any other program, just accept it and continue. The Installation Wizard shows a protocol of its activities. While installing all components, the Installation Wizard has to install a new driver for a virtual network card. Since Windows XP drivers are not only digitally signed, the system also requests either a valid signature or explicit confirmation of installation by the administrator. This time it is about the»tap-win32 Adapter«for OpenVPN. Figure 110: Installing TAP-Win32 Adapter Just continue with the installation of OpenVPN. As the result of this installation there is a new entry in your Network Connections folder. Installed is also a bunch of files and programs in your program files folder, and a new service for OpenVPN. This service is configured to start "Manually", and is covered in a later section. Figure 111: OpenVPN Adapter Network 9.2 NetCom OpenVPN Configuration The next task is to configure the NetCom for encrypted communication. It is assumed the NetCom is already configured for the network. At this step it does not matter if the communication is via Ethernet (Cable) or via WLAN antenna (Wireless), as is mentioned above. Open your web browser, and go to the address of the NetCom Server. Select the Tools page, and activate the option of DebugLog (section above). This is not required for operation, but will help to see what happens on the NetCom. Next go to the Server Configuration page, and scroll to the section of OpenVPN (section above). Check all parameters to be the same as in the figure 65 above. Open the Configuration-Settings of the Encryption-Key (figure 67), and click the Show button to display the current key. Save the key in OpenVPN config, in your program files folder. Use April 2012 NetCom PRO User Manual 122

123 9 OpenVPN Encryption the suggested name of»storedkey.cfg«. Select the Encryption by "AES-256-CBC", which is the default. Warning: When the NetCom is configured for OpenVPN operation, there is no access or configuration without the valid key. Be sure to have all information saved to your system, before enabling the encryption. Otherwise the only way back to normal access is by setting the "Factory Defaults". Then enable the Logging for NetComs OpenVPN function. Save all changes to the NetCom. Note: OpenVPN function is not enabled so far. This final step is done when everything else is ready, including the configuration of OpenVPN. 9.3 OpenVPN Configuration OpenVPN may be started in several ways. One option is the command line, which has the most flexibility. The next option is to use the Context-Menu of the configuration file, and finally the installed service for OpenVPN will also open the connection. All three methods are covered in short. All details about that are given in the documentation on OpenVPN Configuration File All installed connections by OpenVPN are defined and enabled by use of a configuration file. In principle they may also be configured by the command line directly, but a file is simpler to handle. So this manual only deals with such a configuration file. remote dev tap ifconfig secret "..\\config\\ storedkey.cfg " cipher AES-256-CBC proto tcp-client verb 3 Figure 112: OpenVPN Configuration File When installing OpenVPN, the wizard already created a template named client.ovpn. Open this template in Notepad, typically this is done by just double-clicking on it. The content shall be like this: Some parameters must be adjusted to the current installation. In the first line there is , which is the real IP Address of the NetCom in the (W)LAN. This IP Address may be replaced by a DNS name, which must be known to the client computer. This is the only parameter to adjust throughout this example, since all others are preset by the example configuration. Also there is 1194 (figure 65). as the TCP port number defined for OpenVPN operation in the NetCom April 2012 NetCom PRO User Manual 123

124 9 OpenVPN Encryption The third line is the local configuration of the virtual network interface. The computer will use as the own IP Address for the interface of OpenVPN, and as the Netmask on it. This matches the , which is configured as the IP Address on the NetCom (figure 65). If several computers shall contact the same NetCom via OpenVPN, each must have a separate IP Address. The other parameters should be left as they are. To connect to more than one NetCom, each connection requires a separate configuration file. So it may be useful to name the file after the serial number of the NetCom. Any name is OK, as long as the extension (the Windows "file type") remains as ".ovpn" Start OpenVPN by Context-Menu This is the moment to open the web browser again, and access the Server Configuration of the NetCom. Go to the OpenVPN Parameter section (figure 65), and carefully double check all values. They must match the example used here. If you are sure, change the first parameter OpenVPN from Disabled to Server. Save the changes, and let the NetCom perform its Reboot. After some time your web browser will attempt to open the Server Configuration page again, but this will fail. This is desired, because now the communication must be done encrypted. The NetCom is still sending answers to PING on the Ethernet (or WLAN), and it will also accept a TCP connection for Debugging on Port Try it by opening a Telnet session to Port And finally the NetCom waits for a TCP connection on Port 1194, to establish a link via OpenVPN. The Installation Wizard of OpenVPN associated the ".ovpn" file type with Notepad to open by double click. It also added an action available via the Context-Menu of the file. Figure 113: Context-Menu of OpenVPN The Context-Menu is available via right click on the file. Select the action "Start OpenVPN" to open the connection to the NetCom. This will start the openvpn.exe program in the "bin"-subfolder of OpenVPN. There will be a console window with a lot of text output, after some seconds it will end in the text: Initialization Sequence Completed April 2012 NetCom PRO User Manual 124

125 9 OpenVPN Encryption At this stage the network connection becomes active and usable. Windows will show this with an icon in the System Tray: The speed of "10.0 Mbps" is a virtual speed. The achievable results depend on many parameters. These include the real network speed, the network load, and the number of connected clients. Figure 114: OpenVPN Connection is active Open your web browser, and enter the IP Address as the target address. The NetCom will answer, and sends the welcome page. Now you have encrypted communication with the NetCom. Anyone else sniffing on the network (LAN, WLAN, Intra- or Internet) will just see data which appears like garbage. It is required to have the encryption key to get readable information. The virtual network connection is active as long as the console window with the openvpn.exe program is open. Just close the windows, and the connection is closed also Start OpenVPN by Command line The most simple way to activate the OpenVPN connection by command line is to use the already prepared configuration file. Open a console window, and change to the "config"-subfolder of OpenVPN. In this folder issue the command to start OpenVPN. CD "Program files\openvpn\config"..\bin\openvpn --config "client.ovpn" Figure 115: OpenVPN by Command line There will be a lot of text output, after some seconds it will read as: Initialization Sequence Completed At this stage the network connection becomes active and usable. Use TELNET or PING to test the connection from a second console window. The encrypted link is closed by Ctrl-Break on the keyboard, or by closing the console window of the openvpn.exe program. Instead of using the Context-Menu to start the connection, it may be preferred to create a link to do the job. The command of this must be "C:\Program files\openvpn\bin\openvpn.exe" --config client.ovpn and the working directory is "C:\Program files\openvpn\config". This link may be placed on the desktop or in the Start Menu. April 2012 NetCom PRO User Manual 125

126 9 OpenVPN Encryption Start OpenVPN as Windows Service There are possible configurations, which require a functional connection to the NetCom Server without a user logged in. The driver for Virtual Ports is already loaded, however it does not immediately contact the NetCom Server. This is done when the serial port is opened. Without OpenVPN active there is no network link to the NetCom, so the serial port can not be opened. Since Windows NT there is a method to start applications when the system is ready to have a user logon. Applications created for this task are called services. When such a Service application needs the serial ports of the NetCom, the network link to the NetCom must be functional. In the case of encrypted communication, this requires the openvpn.exe program already started. Figure 116: OpenVPN as Windows Service The Installation Wizard also installed a Windows Service for OpenVPN in the Services applet of the Control Panel. The Startup Type is defined as "Manual", so it does not start without special user interaction or required by a dedicated application. When the openvpn.exe program is started by means of this service, it scans the "config"-subfolder for configuration files of type ".ovpn". Each file causes OpenVPN to establish a connection, at least it attempts to do so. If the NetCom is not available at that moment, OpenVPN will try again and again. When the NetCom becomes available, the connection is established. Figure 118: Service Options Figure 117: Start OpenVPN Service For the first test start the Service manually by click on the "Start" link. Windows displays the progress. The connection of OpenVPN will be opened. Verify this by web browser or PING. When April 2012 NetCom PRO User Manual 126